September 23, 2023 • 52 mins
You might not think your car’s odometer is that exciting, but it’s actually the modern incarnation of an ancient invention with roots in China and the Greco-Roman world. Join Robert and Joe as they discuss the invention of the hodómetron and the li-recording drum carriage in this classic invention-themed episode of Stuff to Blow Your Mind. (originally published 09/06/2022)
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Speaker 1 (00:06):
Hey you welcome to Stuff to Blow Your Mind. My
name is Robert Lamb.
Speaker 2 (00:09):
And I'm Joe McCormick, and it's Saturday. We are going
down down into the vault for an older episode of
the podcast. This one originally published on September sixth, twenty
twenty two, and it is about the invention of the odometer.
Speaker 1 (00:24):
Yeah, and that. Don't stop right there and think, Okay,
a dometer my dashboard of my car, the most boring
thing in the universe. No, no, no, this one gets weird.
I highly recommend it. This one goes into the ancient world.
There's some strange devices you're gonna have a lot of
fun with.
Speaker 3 (00:40):
Welcome to Stuff to Blow your Mind, a production of iHeartRadio.
Speaker 1 (00:50):
Hey, welcome to Stuff to Blow your Mind. My name is.
Speaker 2 (00:53):
Robert Lamb and I'm Joe McCormick.
Speaker 1 (00:55):
Today on Stuff to Blow your Mind, we have another
invention themed episode for you. We're going to be talking
about something that might initially seem frightfully dull or at
least very commonplace, and that is the odometer.
Speaker 2 (01:08):
I mentioned this to Rachel earlier and she was like, oh, yes,
the device that measures odors.
Speaker 1 (01:15):
Yes or odos if you were to read the word wrong,
you might think it says odometer, but it's yes, the odometer.
So everyone out there, you probably know this device best
is the little counter in your vehicle that records how
far you've driven. And I think we tend to think
of this invention mostly as a self centered device. It
tells us how far we've driven on our trip, how
(01:37):
many miles or kilometers we've racked up on our vehicle.
But you know, there's another way of looking at the odometer,
and this, certainly this is something that plays into the
history of the invention and also our attempts to understand
its place in the ancient world, is that an odometer
can also be a method of determining distances on given routes.
(01:59):
It's something that turns burns a vehicle into a tool
for measurement.
Speaker 2 (02:03):
Right, So it's it gives you information that would be
useful to other people, because I mean, in the ancient world,
you don't have Google Maps or anything. You might know
that there are two cities, and you might know that
you get from one of them to the other by
following the road to the west, but you might not
know how long it's going to take. You to get
from one to the other. So it would be very
(02:24):
useful if you actually had some standard distance measurements that
would allow you to estimate the length of the journey
and to know how much you need to pack for
the journey and so forth.
Speaker 1 (02:34):
Yeah, we've talked it before about some of the important
things that make up an empire and make an empire
or a kingdom function, and there are things like standardized measurements,
of course, and standardized currency. But another thing that would
be useful is indeed, like you say, to know how
long it takes to get from one place to another,
(02:55):
what is the distance from one place to another, from
border to border, from port to capital, from frontier to ford,
and so for forth. And this is the kind of
thing that would of course be important for warfare, but
also for trade and just general management of a given territory.
So on one hand, you can imagine this situation, and
you can and you can think about what a nodometer is,
(03:18):
and knowing that an odometer has some of its history
in the ancient world, you might think, well, this is
the this is the route we take to get to
the invention. This is the necessity that is the mother
of this invention. But this doesn't necessarily seem to be
the case, as we'll discuss as we look at its history,
both in the East and in the west. Now, I
think it's we're thinking at least just a little bit
(03:40):
about maps in cartography here, because it's easy for the
mind to go there, like I need to know the
exact distance between X and Y because I want an
accurate map, right to kind of go hand in hand
when we think about maps today, Like even if I'm
looking through a Dungeons and Dragons book, I have a
map of some sort of fantastic region, and then I
have a little indicator to tell me exactly how how
(04:03):
many miles and inches or something to that effect.
Speaker 2 (04:05):
Oh, once you get into D and D, though, I
feel like it's often very loosey goosey about travel distances.
Speaker 1 (04:12):
Oh yeah, and I and as a when I am
dungeon mastering, I am also I hate it when there's
like a really specific question about distances, like well, is
it is it one mile or two mile? It's like,
I don't know, it just it's however long it takes
to get there.
Speaker 2 (04:26):
But any well, my experience is you want to you
want to take a cueue from the DM Basically like,
is this a journey where things will happen on the
journey or a journey where we will just magically arrive
at the destination.
Speaker 1 (04:38):
Yes, sometimes the magic is in the journey, but sometimes
it most definitely is not. So thinking about this the
situation about figuring out knowing what the distances are between
one place and the other, and thinking about the role
of maps in the ancient world, I turned to one
of my favorite go to texts for a lot of
this sort of thing, Brian Fagan's The Seventy Great Inventions
(04:59):
of the Ancient World, and several different chapters in there
that deal with measures and maps, and Fagan and his
co authors point out, I think a few important things
about ancient maps that we might want to have in
our head as we proceed. So, first of all, they
point out, the Chinese maps of old were more about
(05:19):
landscape features. So the journey from X to Y is
more about the details of the landscape and the markers
that are passed on the way.
Speaker 2 (05:28):
Yeah. That makes sense, navigating by landmarks.
Speaker 1 (05:31):
Yeah, And so the maps would reflect that. Another thing
they point out is that while local maps in the
ancient world were one thing, as were specialized maps. Broader
maps of the world or region were not really part
of the overall ancient approach to maps. There were no
regular standards of map making, and there were no general
purpose maps. And this is one quote from the book
(05:55):
I thought was rather telling quote between them rulers, general sailors,
and traders evidently all but ignored the practical assistance that
maps could afford them.
Speaker 2 (06:06):
That's surprising.
Speaker 1 (06:07):
Yeah, I think hindsight's twenty twenty. But yeah, it's interesting
to look back and think about what benefits this broader
approach to maps, general purpose maps, etc. Could have afforded them.
So I think all that's worth keeping in mind as
we proceed here. None of this is to say people's
doing these eras were not concerned with precise distances, but
the relationship with exact maps wasn't quite the same as
(06:31):
what we have now now.
Speaker 2 (06:33):
Another way of thinking about what came before is that
there certainly were ways of measuring long distances before the
invention of the mechanical odometer, though there is some question
about the relative accuracy of early mechanical methods versus pre
mechanical methods, and one case study here that I think
we should look at. It's a very interesting puzzle that
(06:55):
emerges if you look at a geography chapter of the
Natural History by our old friend Plenty the Elder. Here
I'll be referring to the Bostock and Riley translation for
those not familiar. Plenty the Elder was a first century
Roman military commander and author, and the Natural History is
(07:15):
an early attempt at creating a sort of world encyclopedia.
So Plenty covers everything from mining and metallurgy to botany
and zoology, cooking, politics. It's just a book of everything.
And in book six of the Natural History, Plenty sets
out to describe quote an account of countries, nations, seas, towns, havens, mountains, rivers, distances,
(07:40):
and peoples who now exist or formerly existed. Very good
chapter heading there. One of the chapters within this volume,
chapter twenty one, is on the nations of India, as
known to Plenty at the time. Again, this is the
first century CE. So Plenty says that India is a
vast country with over one hundred kingdoms, dozens of rivers,
(08:03):
uncountable mountains, but he will undertake to describe some of
it by following the path of Alexander the Great, who
led a conquering army to India about four hundred years earlier.
So plenty rights. Quote. However, that we may come to
a better understanding relative to the description of these regions,
(08:23):
we will follow the track of Alexander the Great. Diagnetas
and Byton, whose duty it was to ascertain the distances
and length of his expeditions, have written that from the
Caspian Gates to hecatom Pylon, the city of the Parthians,
the distance is the number of miles, which we have
already stated, and he mentioned a number earlier. Then he
(08:45):
goes on and that from thence to Alexandria of the Arii,
which city was founded by the same king, the distance
is five hundred and seventy five miles, and from thence
to Prophthesia, the city of the Dragnai, one hundred and
night ninety nine miles. And from here he just goes
on and on, listing distances. It's this many miles to
(09:06):
the next city, and this many miles to the next city.
So he attributes all of these numbers, all of these
distances in miles that he comes up with for this
path leading into India to these two figures Diagnetis and Byton,
who were these guys well? They were known as Bimetists,
coming from the Greek word meaning step or pace. I
(09:31):
looked up Bimetists in the Oxford Handbook of Classics, and
the entry does identify them as the surveyors essentially of
Alexander the Great, and names a few other ones. In
addition to the two I already mentioned Byton and Diagnetis.
It also names Philonides of Crete, who it says in
a side note, was a celebrated distance runner. And the
(09:54):
entry also notes that the two figures who worked for Alexander,
Byton and Diagnetis, as well as some others quote had
literary aspirations. Their measurements of key distances in the Empire
comprised an archive later controlled by Seleucus. The first individual
Bematists published their observations in monographs termed stathmoy or Stages,
(10:18):
which combined precise calculations of distance with more exotic reports
of the flora, fauna and customs of the Empire. The
latter tended to the outrageous, but the measurements were of
lasting value and provided Eratosthenes with the framework for his
geography of Asia. Aritosthenes, you might recall, was an early figure,
(10:38):
a Greek philosopher who with pretty startling accuracy, calculated the
actual size of the sphere of the Earth. And he
did that just using knowledge of the distances between locations
of different latitudes and then the use of the angles
of sun dials. Basically, So, how did the Bemtists actually
(11:03):
measure distances in the time of Alexander the Great? Well,
I've seen some disagreement on this. Some sources imply that
they simply counted paces, so you'd walk and count how
many steps you took, while others suggest that they used
some kind of mechanical device. One of the weird things
is that, as far as we can tell, most of
(11:24):
the distances recorded by bimetists such as Byton and Diagnetis,
as well as others from the ancient world, are surprisingly accurate.
On this point, I want to quote a book I
was looking at by an American historian named Donald W. Ingalls.
The book is called Alexander the Great and the Logistics
of the Macedonian Army, from the University of California Press
(11:47):
in nineteen seventy eight, and explaining a table in his
book of the Bimetists different estimates of the distances between
cities on this route, Ingles rights quote the overall accuracy
of the Bimetists measurements should be apparent. The minor discrepancies
of distance parentheses only one point three percent from herot
(12:08):
to begram can be adequately explained by slight changes in
the tracks of roads during the last twenty three hundred years.
The accuracy of the measurements implies that the Bimetists used
a sophisticated mechanical device for measuring distances, undoubtedly an odometer,
such as described by Heron of Alexandria. So there's a clue.
(12:31):
Ingles here says, Look, the distance is given by these
people who worked for Alexander the Great and other Bimetists
of the era. They are just too accurate. They are
too good to be the result of trying to count
your steps and estimate from that. They have to be
using some kind of machine that we don't know about,
and one good candidate is a machine like the one
(12:52):
described later by Heron of Alexandria.
Speaker 1 (12:56):
Now, this idea that they may have simply been walking
on hand. I can't help but think of the Monty
Python ministry as silly walks and imagine like a specific,
ridiculous but regular gait that they're using. And if they
were super focused on their steps and counting their steps,
maybe that would explain why wrote the reports of flora
(13:17):
and fauna are so outrageous. They're like, well, it was
three thousand, eight hundred and seventy six steps, and to
the left there may have been a dragon. I'm not sure.
I was just really focused on these steps and getting
this step count right.
Speaker 2 (13:30):
I mean, descriptions of local flora, fauna, and peoples of
the world are notably hilarious throughout all kinds of ancient texts,
so including Plenty himself. He loves to talk about people
who had like eyes in their stomachs and stuff.
Speaker 1 (13:46):
Yeah.
Speaker 2 (13:46):
I keep hoping one day I'll come across a passage
in Plenty where he mentions people who have crab claws.
I haven't found that yet.
Speaker 1 (13:54):
Oh, I have to have to look into that. I mean,
because you mentioned it's of course not just Plenty in
his writings, and that he's sourcing. And we've discussed similar
things in Chinese traditions as well, so there have to
be some crab claud individuals out there somewhere, but.
Speaker 2 (14:08):
Okay, sorry, Hero or Heron of Alexandria. Multiple sources I
found point to a device described by this first century
mathematician and inventor, sometimes known as Hero, sometimes known as Hroon,
but he was from Alexandria, Alexandria, Egypt. As you can
tell by the name. A lot of inventions are attributed
to Hero, though some of the most famous ones probably
(14:31):
predated him, and he just described them in lectures and writings,
and then later that gets sort of mistaken for him
having actually invented the thing in the first place, in
the latter category. One example, in fact, one of the
most famous devices associated with Hero is the Eyala pile,
which is a type of early steam engine converting the
(14:52):
power of steam into rotational energy. Basically, it works by
you've got a big cauldron this full of water, and
then you put a i underneath it, and then that
cauldron is connected by pipes to a sphere that can
rotate around the pipes, and then the sphere has two
little exhaust nozzles that allow steam to escape as the
(15:15):
water boils and turns into steam. And expands. But the
way the nozzles are oriented, they're oriented in the same
rotational direction, so as it gets hotter and hotter in
the cauldron and the steam pressure builds up, it spins
the sphere faster and faster.
Speaker 1 (15:31):
Yeah, there are a lot of images of this, as
I recall. I remember seeing a cool wood cut of this,
I think at one point. But it has the look
of a novelty of a device that's illustrating the principle here,
but of course not putting it to the sort of
work that later steam engines would for sure.
Speaker 2 (15:51):
Yes, and though the eolopile is often associated with Hero,
I think this is something that he very like did
not actually invent. It was just something he described that
already existed. But we have talked about other machines possibly
invented by Hero in previous episodes. One that I remember
(16:11):
is that Hero of Alexandria is credited with inventing the
first vending machine, which strangely was also a piece of
religious technology. It was a machine designed to dole out
limited portions of sacred water within Egyptian temples when a
devotee would insert the right amount of coinage. So I
(16:32):
think You'd put a five drachma or five drakma piece
in through a coin slot, and then that would operate
a weighted lever that would dispense a certain amount of
holy water, and then once a certain amount of water
had gone out, the machine would tip over, and then
it would close the valve and stop dispensing. Though even
in this case I read that it's actually possible Hero
(16:52):
was simply describing a device that had already been invented
by Tacbis of Alexandria in the third century BCE. So
a lot of ancient inventions, it's often hard to tell
if somebody actually invented something or if they're just talking
about something that already existed. Right Anyway, I found multiple
references to Hero either inventing or describing an odometer, as
(17:14):
evidenced by a passage he wrote in a minor work
called the Dioptera, which I wanted to find the full
text for, but if it has been translated into English,
I was unable to find it, so I don't know
if that even exists in English. But regarding this machine
he describes in the diopter again, the hero is first
century CE. A couple of caveats, one is that Hero
(17:38):
was definitely not the first known author to describe an
odometer in Greek. In the Greek and Latin Corpus, the
Roman engineer Vitruvius, who lived in the first century BCE,
so century before Hero, also describes an odometer, though in
a slightly different way. I'll get into the differences in
a minute. But even Vitruvius does not claim to have
(18:00):
invented the device out of whole cloth. And then there's
a second caveat which is that remember again Ingles making
the comment that Alexander the Great's bimetists must have had
a device like Heroes. The problem here is that Hero
of Alexandria and Vitruvius both lived long after the conquest
of Alexander the Great. So if it's true, as Ingles
(18:21):
suggests that these bimetists used a mechanical odometer similar to
the one described by these engineers and authors, they would
have been using some kind of earlier device similar to
Heroes or Vitruvius, is not something that Hero or Vitruvius invented. Now,
an interesting source I found on these two device descriptions
(18:43):
is a book called Technical Exprascis in Greek and Roman
science and literature the written Machine between Alexandria and Rome.
This is by an author named Courtney Roby from Cambridge
University Press, twenty sixteen. Courtney Roby is a professor of
classics at Cornell and in this book, this is in
(19:03):
the context of explaining patterns of composition in Greek and
Roman technical books, how in different times and cultures there
were different standards and uses for technical explanation of machinery.
Hero and Vitruvius both wrote books describing odometers. I mentioned Heroes,
but the earlier mentioned by Vitruvius comes in a book
(19:25):
called on Architecture, and according to Roby, Vitruvius himself acknowledges
that the odometer is quote part of a technological tradition
handed down from predecessors. Some authors have suggested that might
mean from Archimedes, but I'm not aware of what evidence
there would be for this, so I'm not sure how
(19:47):
strong that suggestion is. Maybe it's just kind of like, oh, Archimedes,
he invented stuff, and maybe it was him.
Speaker 1 (19:52):
Yeah. I think sometimes we see in different traditions we
have these noted inventors, noted minds, and they kind of
become mythic magnets for various ideas and inventions.
Speaker 2 (20:05):
But there might be some good reasons for thinking or comedies.
I just don't know if there is. I did not
turn it up. The basic principle, how does this odometer work?
So you've got a chariot wheel. Odometer typically has a
wheel of some kind that is rolling on the ground
and that's your basic point of contact with the earth
(20:27):
to get the the baseline measurement of distance. So you've
got a chariot wheel of a fixed size two Roman
feet in radius, which Vitruvius says gives the wheel a
circumference of approximately twelve point five Roman feet. So if
the radius is two, that's four times pie, which is
(20:47):
about twelve point five six. So when Vitruvius has twelve
point five Roman feet, he's sort of approximating in his explanation.
But anyway, each time the chariot wheel makes a full revolution,
it will advancets a cogwheel by one cog position, you know,
one tooth advances, and the cog wheel has a fixed
number of teeth, meaning that it will make a full
(21:10):
revolution once the wheel has traveled one Roman mile every
time this cog wheel makes a full revolution, it will
advance a gear that pushes a single small object like
a pebble or a bead into a receptacle. And then
at the end of the journey, you simply have a
human count up the beans, you know, count up whatever
(21:30):
the little pebbles or beads or beans are to know
how many miles you've gone. And I want to make
a note. This seemed interesting to me that this is
the principle of using a system of gears as a
type of analog computer, similar to the use of gears
in the ancient astronomical computer known as the Antikythera mechanism.
(21:52):
We discussed this in an episode we did sometime in
the past couple of years. It might have been in
the Creature of the Gear episode about biological gears. But
the idea that we often think of a gear as
something that creates mechanical advantage, and it certainly does do that,
but a gear can also manage ratios between numbers, like
(22:12):
a gear can do math for you, and that's what
it's doing in the case of this odometer.
Speaker 1 (22:18):
Yeah, I love these these examples of the from the
ancient birth of the odometer or possible birth of the
odometer in some of these instances, because it seems it's
kind of like we have the wheel turning on the road,
and then it's a question of could we put that
wheel to use, Like the wheel is already in a
sense marking the distance in its revolution, and in that
(22:40):
it's kind of like the heavens. It's like the sun,
it's like the moon, it's like the cyclical movements all
around us that mark the passage of time.
Speaker 2 (22:49):
Yeah, you just need to correlate something with like a
fixed number of teeth that you can count to those
pre existing revolutions, and then you take those teeth to
do some kind of war that will help you keep
the count, like dropping a bean in a bucket or
advancing a dial on a fixed face that has a
number printed on it.
Speaker 1 (23:07):
Yeah, and you can imagine that in the ancent mindset,
like you would have realized if we could harness this,
like this is better than counting your steps. There's a
regularity to this that would be harder to achieve through
other means.
Speaker 2 (23:23):
Totally.
Speaker 1 (23:23):
So.
Speaker 2 (23:24):
Vitruvius describes a machine roughly like that. Hero later describes
a similar machine, but there are some interesting differences in
how the two authors present their explication. For example, Vitruvius
describes his odometer with fixed dimensions. The wheel is four
Roman feet in diameter, the circumference is approximately twelve point
(23:45):
five feet, and so forth. And here I want to
read a passage from roby quote. Rather than providing a
mathematical formula whereby the odometer could be adapted to any
desirable or available wheel size, as Hero does for his
own description of an odomo, Vitruvius avoids formulas and geometrical
language by specifying the wheel diameter and circumference as fixed numbers.
(24:08):
That is to say, the version of the odometer he
gives his reader is presented as the exact device transmitted
from his quote predecessors, not a jumping off point for
experimentation with the type of device. And she goes on
to explain this as typical of the difference between Latin
language technical literature from this period and Hellenistic technical literature.
(24:32):
Works in Latin tended to be exact descriptions of existing devices,
rather than demonstrations of principles and scalable instructions for building
new machines. The latter. The scalable instructions and explication of
principles is more like what Hero of Alexandria presents. Instead
of having fixed dimensions, his explanation is about how to
(24:55):
apply the idea of an odometer to different scales and use,
with the numerical figures being ratios rather than measurements. So
Hero's goal was to represent these relationships between the different
sizes of the wheels and the connected gears, and then
to read one final passage from Roby quote. Hero's description
(25:16):
allows mechanical flexibility as well. He suggests how to extend
the number of cogs in the odometer, which can radically
enhance its measuring capacity. On the other hand, he notes
that it is pointless to make an odometer that measures
a greater distance than its vehicle could cover in a
single day, as it is easiest to just start the
count over each morning, which I like. That's very practical,
(25:40):
but it also flags an interesting difference here. They're just
different assumptions about the reader the text. In a more
Hellenistic tradition, or as Hero does, it might be geared
more toward a select audience of highly educated polymaths who
would be expected to take the engineering principle and then
vary it to their needs, whereas the Latin Roman tradition
(26:03):
is describing an exact device in a more accessible way
that's easy to replicate but offers less deep understanding and flexibility.
But I wanted to come back to a kind of
a lingering question about Alexander's bemtists, whether they used a
mechanical odometer or not, And the question is which is
(26:23):
actually more accurate. You might assume a mechanical odometer is
more accurate, but I've read some arguments that actually human
pacers would be less prone to error over a long
distance than a primitive mechanical device would be. Now, obviously
the best possible scenario would be like to have the
odometer on a modern car. You know, something that is
(26:46):
highly accurate, very well calibrated, a highly accurate modern device
that's going to give you the best reading. But obviously
something built in the fourth century BCE would have significant
enough inaccuracy in its measurements that this would cause problems
over great distances. And so the idea is that any
(27:06):
inaccurate measurement in a mechanical device would just build up
and up over many, many miles on a great journey,
like if the circumference of your wheel is slightly too
long over thousands of miles, it will start to significantly
underestimate the distance traveled. Meanwhile, I think the idea at
least is that human biobemitists literally counting their steps will
(27:28):
also have inaccuracy, maybe inaccuracy relative to some reference length
of a single pace, but that inaccuracy will go both ways.
Steps that are too long and then steps that are
too short, and those will average out over time. That's
the argument at least, and I see the logic here,
and I admit that I'm not a genius at statistics,
(27:49):
so I could be wrong. But my reaction is that
I think this could also be mistaken because it would
tend to assume that the human pacers inaccuracy will not
be consistently biased, either above or below whatever the reference
pace length being used is. So I think this logic
might work if you had like a group of a
(28:09):
thousand people walking, and then you had all of them
count their steps, and then you averaged all of those together.
But if it was just a single person, I would
tend to think that their personal count might be biased
more in one direction or another. They would just tend
to have longer than average or shorter than average steps,
and that even a pretty primitive machine would be better.
(28:32):
But I don't know.
Speaker 1 (28:33):
That's fascinating. Yeah, I don't quite know what to make it, because, yeah,
I can see what they're getting at with the idea
that some sort of a basic mechanical flaw in an
ancient odometer device that you would just consistently get the
wrong number, and then that would build up over time,
and then yeah, when it comes to the actual steps
(28:55):
and the counting of those steps by an individual or individuals,
you'd have, you know, a little in one direction, a
little another direction, but it would sort of even out. Yeah,
it's fascinating to think about.
Speaker 2 (29:06):
I mean, I think it would be more likely to
even out if you were talking about a group of people,
like a large group of people all average together. Yeah,
I don't know if that'd be the case for a
single person. Anyway, whether or not they were using mechanical odometers,
ancientdematists did a not at all bad job of measuring
different distances between milestones between cities, and it's possible they
(29:30):
were helped in this task by devices like the ones
described by Vitruvius and Hero. But ultimately, I think we
don't know for sure if they use these devices or not,
and if they did, we don't know for sure who
invented these ancient odometers. It's one of those questions, you know,
there are many inventions where we just don't know where
(29:50):
they came from.
Speaker 1 (29:51):
I wonder too if it might have been a situation
where they use both where they're specialist in their field.
So perhaps like specialist in other fields, they're using more
than one method and then comparing the numbers and figuring
out some sort of more accurate measurement based on the two.
Speaker 2 (30:10):
Yeah, that could be. I don't know, But anyway, it's
really impressive that in what is like the third or
fourth century BCE, we've got people getting like really accurate
estimates of travel distances that are on the order of
hundreds of miles.
Speaker 1 (30:25):
Yeah, that's fascinating. Now, all this is going on in
the Greco Roman world, but as we've partially alluded to already,
there's also a history of the odometer in Chinese civilization
as well. In particular, the device in question is the
Lee recording drum carriage. Now, this is sometimes attributed as
(30:47):
an invention of Zhonghang, who lived seventy eight through one
thirty nine C. This is a Chinese polymath and court
astronomer in the Eastern Han dynasty. This is an individual
we've talked about before because there are a number of
different inventions that are attributed to him, one of which
was an early form of earthquake detection device. He had
(31:12):
an important role tending calendars and celestial events, aiding the emperor,
who of course ruled at the mandate of heaven, so,
you know, maintaining the balance between cosmos and civil life.
And this is a period of time that sometimes referred
to as the Golden Age of Chinese history, for centuries
of economic prosperity that saw the traffic of goods and
(31:34):
ideas across the Silk Road. He was an inventor, a poet,
and an early scientist. We have an older invention episode
about the earthquake detection device, and I was looking back
at some of our notes and I'm reminded that you
shared some of his poetry in that episode.
Speaker 2 (31:49):
Oh I don't remember that now. Was it good poetry?
Speaker 1 (31:52):
Oh? Yeah, yeah, it's good stuff. So he's credited with
a number of inventions innovations and achievements. He wrote a
treatise on mystical law the Cosmos, which included the theory
that the moon did not emit light, but reflected the
light of the sun. And he's also sometimes attributed as
the inventor of the Lee recording drum carriage, which again
(32:12):
is this odometer of sorts in Chinese history. Now it
is worth noting that kind of like the situation with
Hero and Archimedes, we have a very famous historical inventor here,
and he's attributed with a number of inventions. And so
I guess the question always lingers, is this an invention
(32:32):
that this individual invented? Is it something that they described
it is something? Is it something that just ends up
being attributed to them because the technology was known during
that time, or it's based on surviving records, etc.
Speaker 2 (32:47):
Yeah, exactly.
Speaker 1 (32:48):
So I ended up looking at some of the writings
of Joseph Needhaim on this. So. Needham lived nineteen hundred
through nineteen ninety five. He was a British biochemist, historian
of science and sonologists who wrote rather extensively on the
history of science and technology in China. His second wife
Lu gives him as a Chinese historian and biochemist, and
(33:10):
she was an important co researcher and co author in
his work. So we're talking multiple volumes that he wrote
during his lifetime. Very very much is life work. So
before we get to the carriage itself, I thought we
might stop to just consider roads in ancient China. So
Needham writes about roads in general in the short Science
(33:34):
and Civilization in China, and he points out that they
were quite comparable to the famous roads of the Romans.
Both empires had extensive road systems that served as a
means of logistically connecting their vast landholdings for travel and trade,
as well as playing an important part is just in
just communication through the empire. That's always something to keep
(33:56):
in mind that the road is also a lane for communication. Now,
both systems, the Roman and the Chinese, fell into long
periods of decay after the third century CE, he points out,
though he writes that while the collapse of Roman roads
had more of a fracturing effect in China, natural and
artificial waterways and some surviving mountain road systems enabled these
(34:19):
far reaching routes of communication to remain open. He also
points out something very interesting about these two independent systems
that this rather awe inspiring and I thought really nicely written,
and it also kind of ties into some of the
stuff we talked about in our previous episode about the
Roman military the Dethroned Emperor series quote. Should the Romans
(34:40):
have ever succeeded in conquering the Parthians and the Persians,
the two road systems might have met, perhaps somewhere west
of Shinjang, but this was not to be. The octopus
like arms expanded independently, each in a world of its own,
their builders, troubled only occasionally by the vaguest rumors of
(35:02):
another system too far away to matter. Zinjohn, by the way,
is in northwest China. That's where he's talking about here.
So yeah, this is such a I love this quote
because it's just imagining these two independent road systems like octopuses,
each doing their own thing, and if you know, world
history had gone a different way, there could have been
(35:24):
a situation where they met. It's crazy to think about,
like roads, I've often thought about. You know, you encounter
a road and where does that road end? You know
that basically goes It's not infinite, but it stretches on
for such a great distance, and to imagine these two
vast systems almost but not quite coming together. Yeah. Yeah,
(35:46):
it's kind of like I don't know if you've ever
played around with us to see like how far one
can drive on a given continent or unconnected continents, Like
at what point do things seem to break down? And
you would have to find some other route to connect
with another road. And I know when you get into
your Asia and Africa, like there are some pretty long
(36:07):
travels by road that are that are possible today. The
road is not going to be necessarily be great the
whole way, but you can do quite a lot. So anyway,
Needam points out that with the odometer or the way measures,
it's a pretty simple proposition from a mechanical standpoint. If
(36:30):
you have the wheel already, and you have row, and
you have if you have roads, you have wheels, then
all it is is quote a system of toothed wheels
constituting a reduction gear train so that one or more
pins revolve slowly, releasing catches at predetermined intervals, and in
the case of this invention, striking drums or gongs, so
(36:53):
the lee recording drum carriage. What is a lee. A
lee is the traditional Chinese measure of distance. Today's standard
eye at five hundred meters or one thousand, six d
and forty feet, but as with the mile in Western traditions,
historically there's some drift over exactly how far it is
supposed to be. But it's standardized today and would have
(37:14):
been standardized under different rules in different dynasties.
Speaker 2 (37:18):
Yeah, standardization of measures does seem like such an important
part of this too, because when I kept thinking about
the idea of a bimitist potentially trying to measure distance
with paces, I'm like, what is So you've got to
have something that's like a reference pace, right, if you
say something is x number of paces long, you've got
(37:39):
to either know how much your pace typically relates to
a standard measure like a mile, or you've got to
be using your paces as some kind of literal standard measure,
like people would know what that number meant.
Speaker 1 (37:53):
Yeah. Yeah, it's the history of measurements alone would be
something interesting to come back to, because, of course you
get into use of various parts of the human body
to form your base measurements, the creation of tools, and
certainly when you're getting into weights for goods and trade,
like some of our oldest data and oldest examples are
all related to that. But then when you start thinking
(38:15):
about these larger measurements, like the measurement between you know,
the fort in the frontier, that sort of thing, like
you can't just count, You can't just have someone go
out there with essentially a ruler and say, all right,
start measuring it off, like you've got to have some
other system. Yeah, yeah, all right. Sonam gets more into
the subject of the Lee measuring card here in Science
(38:39):
and Civilization in China, Volume for Physics and Physical Technology,
Part two Mechanical Engineering, and yeah, it gets into the
nature and origins of the Lee recording drum carriage. He
cites several sources and pose in Some of these are
sources that go into more detail, others just kind of
mention it in passing and points out that that many
(38:59):
of them of the carriage, yet they don't actually describe
the mechanism employed. In at least one case, it shows
up as a math problem. It's something along the lines
of if the Lee recording drum carriage were to travel
between this city and this city, how many times would
the gong sound? That sort of thing. The concept seems
to date back to the Han dynasty, and this is
(39:21):
where the attribution to Zunghing seems to come into play.
But when the carriage is described, it's generally described as
a carriage drawn by four horses, and it works based
on multiple cogged wheels, some vertical and some horizontal, you know,
all of course, much like the earlier example and the
Greco Roman traditions we were discussing, you know, it's tied
(39:42):
to the movement of the wheels. In the simpler version
of this carriage, it's said that there is a wooden
man in the carriage who is mechanically made to strike
a drum with the passage of each lee. So the
wheels are turning, the cogs are turned, learning there's a
mechanical wooden man inside who like a music box, he
(40:05):
is going to mechanically strike a drum. In this case,
every time one lee has.
Speaker 2 (40:10):
Passed, beat that. Vitruvius, you did not have a wooden man,
did you.
Speaker 1 (40:16):
Later, a more complex version is described as being two
stories in height, so it's a carriage that has two stories,
and each story has its own wooden figure. The lower
figure strikes a drum every lee, while the higher figure
rings a bell every ten lee.
Speaker 2 (40:33):
Okay, So one difference that occurs to me here is
this would still if it's keeping track of the distance
in an accurate way, but doing so by making a
sound instead of by say, accumulating pebbles or beads in
a container. It's something that you would to some extent
(40:54):
need to continuously keep track of as you're traveling, Like
it would still require effort, full engagement of the memory
by somebody doing the traveling, right.
Speaker 1 (41:04):
That's right. That's based on my reading here of Needham.
I don't think there's any indication that it was spitting
out like you know, balls or pebbles that could then
be counted later, or that was anyway recording how many
les it passed. It was just a you know, a
ringing of a bell or the striking of a drum
(41:25):
based on the intervals traveled.
Speaker 2 (41:26):
Which would still be useful, but would require more work
than or at least work spread out over a longer
period of time, rather than say like a single counting
activity in between travel segments.
Speaker 1 (41:39):
And in this we get into one of the big
questions about the lee recording drum carriage, and that is
was this a device that was at all originally intended
to measure distances? Or was it you? Or was it
more about music? Was it more about novelty? Was it
why was the technology employed so again this These writings
(42:02):
are typically revolving around the Han period or perhaps a
little earlier, but the lee measuring drum carriage was not
known as such until later, and Needham discusses that this
might mean that the invention was in fact more expressly
for musical performance rather than the measurement of distances. Again,
at least during this time period. It may have changed
(42:23):
later when someone realized, oh yeah, we can just count
how many strikes of the drum, we can count how
many rings of the bell, and then that's data that
could prove useful. But he stresses that you know, these
are still interconnect interconnected possibilities and if you're if you're asking, well,
why would they do that? Like why build a carriage
like this? And why does it remain something other than
(42:44):
just like a one time novelty, Like why is it
written about so much? And he points out that music,
of course, is often part of a procession, and he
stresses that quote carriages for musicians whether mechanized or not
survived in imperial processions through many subsequent dynasties. So the
idea here is that the mechanical version here develops from
(43:07):
non mechanical carriages with human musicians inside them. Imperial fleets
of vehicles, as he refers to them, would have likely
included palace officials and so forth, but also entertainers musicians.
So as everyone's traveling down the road, there's music, and
at some point someone says, hey, well, we could build
(43:28):
some gears. We could make a mechanical musical man inside
one of the carriages.
Speaker 2 (43:33):
Putting those flesh musicians out of the job.
Speaker 1 (43:35):
Well, I don't know if they'd be completely out of
the job, because you know, these the mechanical musicians can
only do so much here. But yeah, for a modern comparison,
we might think of a parade float as a counterpart
to something like this. It does sound a lot like
a parade float. It would have been, according to one account,
painted red and decorated with flowers and birds. It's described
(43:58):
as being escorted by eighteen men, and there would have
been a phoenix headed carriage pole on it. So this
was not clearly not something that was like a Google
Maps vehicle that was out there just to perform a task.
It also it said that it looked marvelous. It's a
joyous vehicle. And once more Needum stress is that we
(44:18):
don't know for sure if it was ever used by cartographers.
It's possible that later on cartographers may make use of
the data that could be provided by this, but we're
not sure. Interesting, so Needham points out that Hero's description
of thedometer did not claim it as a new invention.
He mentions Vitruvius and then mentions that after Hero Vitruvius,
(44:40):
the odometer appears in Western Europe during the fifteenth century.
So it's kind of not really on the Western European
radar for a long period of time, or doesn't seem
to be based on surviving histories, and then it re emerges.
Quote the pattern is therefore the same as that which
we have repeatedly met with i e. Greek antecedent paralleled
(45:01):
or followed by followed at short distance by Chinese developments
which continue throughout the medieval period, and then a reawakening
of the subject in Europe. So in this he's touching
on something that was kind of a career spanning question
for him is often referred to as the need Him question,
and that the question is basically why didn't China beat
(45:22):
Europe to the scientific revolution. He's been a fair amount
of his work thinking over this and looking to answers
and Chinese social institutions and more. Though as reading that,
synologist Nathan Sivin, who would have been I think at
times a collaborator with Needham, pointed out that, you know,
the whole thing is basically a why did an X
(45:43):
happen in history? Question, which, by some estimates is less
than a fruitful enterprise. You know, you get into all
sorts of complex butterfly winging, flapping concerns when you start
asking questions like that. They can be kind of nifty
head scratchers, but perhaps they are not the best exercise
for an historian. But at any rate, the need Hum question,
(46:04):
you see it mentioned a lot in discussions of the
history of Chinese science. Now, I do want to note
in reading about all this, I also read some material
for Needum about another interesting wheeled vehicle in Chinese history,
and that is the South Pointing chariot. But that's one
we're gonna have to come back to. But yeah, the
(46:24):
idea of a chariot with another mechanical man on it,
but this mechanical man always points south ominous.
Speaker 2 (46:31):
Okay.
Speaker 1 (46:33):
So we're not going to go through the exhaustive history
of the odometer in recent centuries, but I thought it
might be useful to point out a few different later
innovations that kind of bring us up to the modern odometer.
There's Pascal's calculator. This would have been an invention or
(46:53):
an innovation by Blaise Pascal. This was sixteen forty five,
not in a dometer per se, but it was a
computation mechanism that entailed rotating toothed gears, and much like
a modern odometer, one complete cycle of one gear caused
the movement of the next gear.
Speaker 2 (47:10):
Okay, So this would have been taking the same principle
by which the ancient odometer worked, but applying it to
general calculation rather than just the movement of a vehicle wheel.
Speaker 1 (47:21):
Right now, in the late sixteen hundreds early seventeen hundreds,
we also see Thomas Savory's nautical odometer. Savory's most famous
invention was the steam engine, but he also devised a
nautical odometer. I actually couldn't find out much about this,
so I don't know. I'm I have to come back
to this one in the future, but because I was
curious on how exactly it would have functioned. Oh interesting, Yeah,
(47:42):
supposedly there was a patent, so it seems like I
should be able to find that patent somewhere. So I
don't know, I'll have to come back to that one.
But this is a fun part because our old friend
Ben Franklin also enters the fray here when it comes
to the odometer. He's come up in more than one
invention come resition, I believe.
Speaker 2 (48:01):
So what was his take?
Speaker 1 (48:03):
So in seventeen seventy five, he was serving as Postmaster
General for the British Previously he had been postmaster of Philadelphia,
and he wanted more data on the shortest routes for
mail delivery. So he basically devised a simple odometer to
attach to his own carriage. And this will for this
(48:23):
reason you'll sometime see, especially some online sources, saying Ben
Franklin invented the odometer. No, it's not accurate in the
least to say Ben Franklin invented the odometer. You could
say he invented unodometer. He certainly whipped one up on
the fly. Here. It seems so every four hundred revolutions
it would register a mile, and the results were apparently
(48:45):
pretty accurate based on what I was reading here. So
at any rate, he was able to use the data
to figure out which route was best for mail delivery.
Speaker 2 (48:54):
Now, one thing I know I saw reference to on
the internet and I didn't know what to make of
this was the idea of a a Mormon odometer.
Speaker 1 (49:02):
Yeah, this was one that that came up for me
as well. The rohdometer from Clayton and Pratt. This would
have been eighteen forty seven. They were pioneers of the
Church of Jesus Christ of Latter day Saints, and they
apparently crafted a simple odometer to measure how far a
wagon train had traveled. So that's it's interesting again. You're
(49:24):
getting into this area where it sounds like people would
find themselves in situations where they could really use an odometer.
And since the knowledge was known, you could create one.
You couldn't go to the store and buy one, but
the principles were out there. The principles were part of
the technological canon, so you could draw on that and
make yourself a functional odometer. In eighteen ninety five Curtis
(49:49):
h Veder came up with a bicycle mounted odometer, the cyclometer,
and then in nineteen oh three we have the Warner autometer,
which I think like the average versions of this, this
was like an actual product. It was a combined odometer, speedometer,
and clock, but it made use of magnetism as opposed
to just pure gear work. So like those are some
(50:11):
of the big more big innovations in the odometer in
recent centuries. And yeah, today the odometer again is something
we tend to just take for granted or we don't
even read it. It just sort of clicks by there
and maybe we check in on it every you know, however,
many thousands of miles, I guess it varies. Some people
are probably more into keeping a close eye in their odometer,
(50:32):
or you have to for work. Obviously.
Speaker 2 (50:34):
I think about seeing those surveyors who have the wheel,
they use the surveyors wheel.
Speaker 1 (50:39):
The surveyor's wheel. Of course I didn't think about that.
That's an obvious innovation to compare to some of these
discussions of the odometer, like harnessing the power of the
wheel for measurement. All right, Well, we're going to go
and close it out here, but we'd love to hear
from everyone out there. Perhaps you have particular thoughts about
the odometer, it's ancient history, it's recent history, tree, or
(51:01):
our modern use of the technology. Write in We would
love to hear from you. As a reminder, our core
episodes of Stuff to Blow Your Mind published on Tuesdays
and Thursdays, and the Stuff to Blow your Mind podcast
feed on Mondays, we do listener mail. On Wednesdays we
do a short form artifact or monster fact, and on
Fridays we do Weird House Cinema. That's our time to
set aside most serious concerns and just talk about the
(51:22):
strange film huge.
Speaker 2 (51:23):
Thanks to our excellent audio producer Seth Nicholas Johnson. If
you would like to get in touch with us with
feedback on this episode or any other, to suggest a
topic for the future, or just to say hello, you
can email us at contact at stuff to Blow your
Mind dot com.
Speaker 3 (51:38):
Stuff to Blow Your Mind is production of iHeartRadio. For
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Apple Podcasts, or wherever you're listening to your favorite shows.
(52:04):
Ratt
Hey you welcome to Stuff to Blow Your Mind. My
name is Robert Lamb.
Speaker 2 (00:09):
And I'm Joe McCormick, and it's Saturday. We are going
down down into the vault for an older episode of
the podcast. This one originally published on September sixth, twenty
twenty two, and it is about the invention of the odometer.
Speaker 1 (00:24):
Yeah, and that. Don't stop right there and think, Okay,
a dometer my dashboard of my car, the most boring
thing in the universe. No, no, no, this one gets weird.
I highly recommend it. This one goes into the ancient world.
There's some strange devices you're gonna have a lot of
fun with.
Speaker 3 (00:40):
Welcome to Stuff to Blow your Mind, a production of iHeartRadio.
Speaker 1 (00:50):
Hey, welcome to Stuff to Blow your Mind. My name is.
Speaker 2 (00:53):
Robert Lamb and I'm Joe McCormick.
Speaker 1 (00:55):
Today on Stuff to Blow your Mind, we have another
invention themed episode for you. We're going to be talking
about something that might initially seem frightfully dull or at
least very commonplace, and that is the odometer.
Speaker 2 (01:08):
I mentioned this to Rachel earlier and she was like, oh, yes,
the device that measures odors.
Speaker 1 (01:15):
Yes or odos if you were to read the word wrong,
you might think it says odometer, but it's yes, the odometer.
So everyone out there, you probably know this device best
is the little counter in your vehicle that records how
far you've driven. And I think we tend to think
of this invention mostly as a self centered device. It
tells us how far we've driven on our trip, how
(01:37):
many miles or kilometers we've racked up on our vehicle.
But you know, there's another way of looking at the odometer,
and this, certainly this is something that plays into the
history of the invention and also our attempts to understand
its place in the ancient world, is that an odometer
can also be a method of determining distances on given routes.
(01:59):
It's something that turns burns a vehicle into a tool
for measurement.
Speaker 2 (02:03):
Right, So it's it gives you information that would be
useful to other people, because I mean, in the ancient world,
you don't have Google Maps or anything. You might know
that there are two cities, and you might know that
you get from one of them to the other by
following the road to the west, but you might not
know how long it's going to take. You to get
from one to the other. So it would be very
(02:24):
useful if you actually had some standard distance measurements that
would allow you to estimate the length of the journey
and to know how much you need to pack for
the journey and so forth.
Speaker 1 (02:34):
Yeah, we've talked it before about some of the important
things that make up an empire and make an empire
or a kingdom function, and there are things like standardized measurements,
of course, and standardized currency. But another thing that would
be useful is indeed, like you say, to know how
long it takes to get from one place to another,
(02:55):
what is the distance from one place to another, from
border to border, from port to capital, from frontier to ford,
and so for forth. And this is the kind of
thing that would of course be important for warfare, but
also for trade and just general management of a given territory.
So on one hand, you can imagine this situation, and
you can and you can think about what a nodometer is,
(03:18):
and knowing that an odometer has some of its history
in the ancient world, you might think, well, this is
the this is the route we take to get to
the invention. This is the necessity that is the mother
of this invention. But this doesn't necessarily seem to be
the case, as we'll discuss as we look at its history,
both in the East and in the west. Now, I
think it's we're thinking at least just a little bit
(03:40):
about maps in cartography here, because it's easy for the
mind to go there, like I need to know the
exact distance between X and Y because I want an
accurate map, right to kind of go hand in hand
when we think about maps today, Like even if I'm
looking through a Dungeons and Dragons book, I have a
map of some sort of fantastic region, and then I
have a little indicator to tell me exactly how how
(04:03):
many miles and inches or something to that effect.
Speaker 2 (04:05):
Oh, once you get into D and D, though, I
feel like it's often very loosey goosey about travel distances.
Speaker 1 (04:12):
Oh yeah, and I and as a when I am
dungeon mastering, I am also I hate it when there's
like a really specific question about distances, like well, is
it is it one mile or two mile? It's like,
I don't know, it just it's however long it takes
to get there.
Speaker 2 (04:26):
But any well, my experience is you want to you
want to take a cueue from the DM Basically like,
is this a journey where things will happen on the
journey or a journey where we will just magically arrive
at the destination.
Speaker 1 (04:38):
Yes, sometimes the magic is in the journey, but sometimes
it most definitely is not. So thinking about this the
situation about figuring out knowing what the distances are between
one place and the other, and thinking about the role
of maps in the ancient world, I turned to one
of my favorite go to texts for a lot of
this sort of thing, Brian Fagan's The Seventy Great Inventions
(04:59):
of the Ancient World, and several different chapters in there
that deal with measures and maps, and Fagan and his
co authors point out, I think a few important things
about ancient maps that we might want to have in
our head as we proceed. So, first of all, they
point out, the Chinese maps of old were more about
(05:19):
landscape features. So the journey from X to Y is
more about the details of the landscape and the markers
that are passed on the way.
Speaker 2 (05:28):
Yeah. That makes sense, navigating by landmarks.
Speaker 1 (05:31):
Yeah, And so the maps would reflect that. Another thing
they point out is that while local maps in the
ancient world were one thing, as were specialized maps. Broader
maps of the world or region were not really part
of the overall ancient approach to maps. There were no
regular standards of map making, and there were no general
purpose maps. And this is one quote from the book
(05:55):
I thought was rather telling quote between them rulers, general sailors,
and traders evidently all but ignored the practical assistance that
maps could afford them.
Speaker 2 (06:06):
That's surprising.
Speaker 1 (06:07):
Yeah, I think hindsight's twenty twenty. But yeah, it's interesting
to look back and think about what benefits this broader
approach to maps, general purpose maps, etc. Could have afforded them.
So I think all that's worth keeping in mind as
we proceed here. None of this is to say people's
doing these eras were not concerned with precise distances, but
the relationship with exact maps wasn't quite the same as
(06:31):
what we have now now.
Speaker 2 (06:33):
Another way of thinking about what came before is that
there certainly were ways of measuring long distances before the
invention of the mechanical odometer, though there is some question
about the relative accuracy of early mechanical methods versus pre
mechanical methods, and one case study here that I think
we should look at. It's a very interesting puzzle that
(06:55):
emerges if you look at a geography chapter of the
Natural History by our old friend Plenty the Elder. Here
I'll be referring to the Bostock and Riley translation for
those not familiar. Plenty the Elder was a first century
Roman military commander and author, and the Natural History is
(07:15):
an early attempt at creating a sort of world encyclopedia.
So Plenty covers everything from mining and metallurgy to botany
and zoology, cooking, politics. It's just a book of everything.
And in book six of the Natural History, Plenty sets
out to describe quote an account of countries, nations, seas, towns, havens, mountains, rivers, distances,
(07:40):
and peoples who now exist or formerly existed. Very good
chapter heading there. One of the chapters within this volume,
chapter twenty one, is on the nations of India, as
known to Plenty at the time. Again, this is the
first century CE. So Plenty says that India is a
vast country with over one hundred kingdoms, dozens of rivers,
(08:03):
uncountable mountains, but he will undertake to describe some of
it by following the path of Alexander the Great, who
led a conquering army to India about four hundred years earlier.
So plenty rights. Quote. However, that we may come to
a better understanding relative to the description of these regions,
(08:23):
we will follow the track of Alexander the Great. Diagnetas
and Byton, whose duty it was to ascertain the distances
and length of his expeditions, have written that from the
Caspian Gates to hecatom Pylon, the city of the Parthians,
the distance is the number of miles, which we have
already stated, and he mentioned a number earlier. Then he
(08:45):
goes on and that from thence to Alexandria of the Arii,
which city was founded by the same king, the distance
is five hundred and seventy five miles, and from thence
to Prophthesia, the city of the Dragnai, one hundred and
night ninety nine miles. And from here he just goes
on and on, listing distances. It's this many miles to
(09:06):
the next city, and this many miles to the next city.
So he attributes all of these numbers, all of these
distances in miles that he comes up with for this
path leading into India to these two figures Diagnetis and Byton,
who were these guys well? They were known as Bimetists,
coming from the Greek word meaning step or pace. I
(09:31):
looked up Bimetists in the Oxford Handbook of Classics, and
the entry does identify them as the surveyors essentially of
Alexander the Great, and names a few other ones. In
addition to the two I already mentioned Byton and Diagnetis.
It also names Philonides of Crete, who it says in
a side note, was a celebrated distance runner. And the
(09:54):
entry also notes that the two figures who worked for Alexander,
Byton and Diagnetis, as well as some others quote had
literary aspirations. Their measurements of key distances in the Empire
comprised an archive later controlled by Seleucus. The first individual
Bematists published their observations in monographs termed stathmoy or Stages,
(10:18):
which combined precise calculations of distance with more exotic reports
of the flora, fauna and customs of the Empire. The
latter tended to the outrageous, but the measurements were of
lasting value and provided Eratosthenes with the framework for his
geography of Asia. Aritosthenes, you might recall, was an early figure,
(10:38):
a Greek philosopher who with pretty startling accuracy, calculated the
actual size of the sphere of the Earth. And he
did that just using knowledge of the distances between locations
of different latitudes and then the use of the angles
of sun dials. Basically, So, how did the Bemtists actually
(11:03):
measure distances in the time of Alexander the Great? Well,
I've seen some disagreement on this. Some sources imply that
they simply counted paces, so you'd walk and count how
many steps you took, while others suggest that they used
some kind of mechanical device. One of the weird things
is that, as far as we can tell, most of
(11:24):
the distances recorded by bimetists such as Byton and Diagnetis,
as well as others from the ancient world, are surprisingly accurate.
On this point, I want to quote a book I
was looking at by an American historian named Donald W. Ingalls.
The book is called Alexander the Great and the Logistics
of the Macedonian Army, from the University of California Press
(11:47):
in nineteen seventy eight, and explaining a table in his
book of the Bimetists different estimates of the distances between
cities on this route, Ingles rights quote the overall accuracy
of the Bimetists measurements should be apparent. The minor discrepancies
of distance parentheses only one point three percent from herot
(12:08):
to begram can be adequately explained by slight changes in
the tracks of roads during the last twenty three hundred years.
The accuracy of the measurements implies that the Bimetists used
a sophisticated mechanical device for measuring distances, undoubtedly an odometer,
such as described by Heron of Alexandria. So there's a clue.
(12:31):
Ingles here says, Look, the distance is given by these
people who worked for Alexander the Great and other Bimetists
of the era. They are just too accurate. They are
too good to be the result of trying to count
your steps and estimate from that. They have to be
using some kind of machine that we don't know about,
and one good candidate is a machine like the one
(12:52):
described later by Heron of Alexandria.
Speaker 1 (12:56):
Now, this idea that they may have simply been walking
on hand. I can't help but think of the Monty
Python ministry as silly walks and imagine like a specific,
ridiculous but regular gait that they're using. And if they
were super focused on their steps and counting their steps,
maybe that would explain why wrote the reports of flora
(13:17):
and fauna are so outrageous. They're like, well, it was
three thousand, eight hundred and seventy six steps, and to
the left there may have been a dragon. I'm not sure.
I was just really focused on these steps and getting
this step count right.
Speaker 2 (13:30):
I mean, descriptions of local flora, fauna, and peoples of
the world are notably hilarious throughout all kinds of ancient texts,
so including Plenty himself. He loves to talk about people
who had like eyes in their stomachs and stuff.
Speaker 1 (13:46):
Yeah.
Speaker 2 (13:46):
I keep hoping one day I'll come across a passage
in Plenty where he mentions people who have crab claws.
I haven't found that yet.
Speaker 1 (13:54):
Oh, I have to have to look into that. I mean,
because you mentioned it's of course not just Plenty in
his writings, and that he's sourcing. And we've discussed similar
things in Chinese traditions as well, so there have to
be some crab claud individuals out there somewhere, but.
Speaker 2 (14:08):
Okay, sorry, Hero or Heron of Alexandria. Multiple sources I
found point to a device described by this first century
mathematician and inventor, sometimes known as Hero, sometimes known as Hroon,
but he was from Alexandria, Alexandria, Egypt. As you can
tell by the name. A lot of inventions are attributed
to Hero, though some of the most famous ones probably
(14:31):
predated him, and he just described them in lectures and writings,
and then later that gets sort of mistaken for him
having actually invented the thing in the first place, in
the latter category. One example, in fact, one of the
most famous devices associated with Hero is the Eyala pile,
which is a type of early steam engine converting the
(14:52):
power of steam into rotational energy. Basically, it works by
you've got a big cauldron this full of water, and
then you put a i underneath it, and then that
cauldron is connected by pipes to a sphere that can
rotate around the pipes, and then the sphere has two
little exhaust nozzles that allow steam to escape as the
(15:15):
water boils and turns into steam. And expands. But the
way the nozzles are oriented, they're oriented in the same
rotational direction, so as it gets hotter and hotter in
the cauldron and the steam pressure builds up, it spins
the sphere faster and faster.
Speaker 1 (15:31):
Yeah, there are a lot of images of this, as
I recall. I remember seeing a cool wood cut of this,
I think at one point. But it has the look
of a novelty of a device that's illustrating the principle here,
but of course not putting it to the sort of
work that later steam engines would for sure.
Speaker 2 (15:51):
Yes, and though the eolopile is often associated with Hero,
I think this is something that he very like did
not actually invent. It was just something he described that
already existed. But we have talked about other machines possibly
invented by Hero in previous episodes. One that I remember
(16:11):
is that Hero of Alexandria is credited with inventing the
first vending machine, which strangely was also a piece of
religious technology. It was a machine designed to dole out
limited portions of sacred water within Egyptian temples when a
devotee would insert the right amount of coinage. So I
(16:32):
think You'd put a five drachma or five drakma piece
in through a coin slot, and then that would operate
a weighted lever that would dispense a certain amount of
holy water, and then once a certain amount of water
had gone out, the machine would tip over, and then
it would close the valve and stop dispensing. Though even
in this case I read that it's actually possible Hero
(16:52):
was simply describing a device that had already been invented
by Tacbis of Alexandria in the third century BCE. So
a lot of ancient inventions, it's often hard to tell
if somebody actually invented something or if they're just talking
about something that already existed. Right Anyway, I found multiple
references to Hero either inventing or describing an odometer, as
(17:14):
evidenced by a passage he wrote in a minor work
called the Dioptera, which I wanted to find the full
text for, but if it has been translated into English,
I was unable to find it, so I don't know
if that even exists in English. But regarding this machine
he describes in the diopter again, the hero is first
century CE. A couple of caveats, one is that Hero
(17:38):
was definitely not the first known author to describe an
odometer in Greek. In the Greek and Latin Corpus, the
Roman engineer Vitruvius, who lived in the first century BCE,
so century before Hero, also describes an odometer, though in
a slightly different way. I'll get into the differences in
a minute. But even Vitruvius does not claim to have
(18:00):
invented the device out of whole cloth. And then there's
a second caveat which is that remember again Ingles making
the comment that Alexander the Great's bimetists must have had
a device like Heroes. The problem here is that Hero
of Alexandria and Vitruvius both lived long after the conquest
of Alexander the Great. So if it's true, as Ingles
(18:21):
suggests that these bimetists used a mechanical odometer similar to
the one described by these engineers and authors, they would
have been using some kind of earlier device similar to
Heroes or Vitruvius, is not something that Hero or Vitruvius invented. Now,
an interesting source I found on these two device descriptions
(18:43):
is a book called Technical Exprascis in Greek and Roman
science and literature the written Machine between Alexandria and Rome.
This is by an author named Courtney Roby from Cambridge
University Press, twenty sixteen. Courtney Roby is a professor of
classics at Cornell and in this book, this is in
(19:03):
the context of explaining patterns of composition in Greek and
Roman technical books, how in different times and cultures there
were different standards and uses for technical explanation of machinery.
Hero and Vitruvius both wrote books describing odometers. I mentioned Heroes,
but the earlier mentioned by Vitruvius comes in a book
(19:25):
called on Architecture, and according to Roby, Vitruvius himself acknowledges
that the odometer is quote part of a technological tradition
handed down from predecessors. Some authors have suggested that might
mean from Archimedes, but I'm not aware of what evidence
there would be for this, so I'm not sure how
(19:47):
strong that suggestion is. Maybe it's just kind of like, oh, Archimedes,
he invented stuff, and maybe it was him.
Speaker 1 (19:52):
Yeah. I think sometimes we see in different traditions we
have these noted inventors, noted minds, and they kind of
become mythic magnets for various ideas and inventions.
Speaker 2 (20:05):
But there might be some good reasons for thinking or comedies.
I just don't know if there is. I did not
turn it up. The basic principle, how does this odometer work?
So you've got a chariot wheel. Odometer typically has a
wheel of some kind that is rolling on the ground
and that's your basic point of contact with the earth
(20:27):
to get the the baseline measurement of distance. So you've
got a chariot wheel of a fixed size two Roman
feet in radius, which Vitruvius says gives the wheel a
circumference of approximately twelve point five Roman feet. So if
the radius is two, that's four times pie, which is
(20:47):
about twelve point five six. So when Vitruvius has twelve
point five Roman feet, he's sort of approximating in his explanation.
But anyway, each time the chariot wheel makes a full revolution,
it will advancets a cogwheel by one cog position, you know,
one tooth advances, and the cog wheel has a fixed
number of teeth, meaning that it will make a full
(21:10):
revolution once the wheel has traveled one Roman mile every
time this cog wheel makes a full revolution, it will
advance a gear that pushes a single small object like
a pebble or a bead into a receptacle. And then
at the end of the journey, you simply have a
human count up the beans, you know, count up whatever
(21:30):
the little pebbles or beads or beans are to know
how many miles you've gone. And I want to make
a note. This seemed interesting to me that this is
the principle of using a system of gears as a
type of analog computer, similar to the use of gears
in the ancient astronomical computer known as the Antikythera mechanism.
(21:52):
We discussed this in an episode we did sometime in
the past couple of years. It might have been in
the Creature of the Gear episode about biological gears. But
the idea that we often think of a gear as
something that creates mechanical advantage, and it certainly does do that,
but a gear can also manage ratios between numbers, like
(22:12):
a gear can do math for you, and that's what
it's doing in the case of this odometer.
Speaker 1 (22:18):
Yeah, I love these these examples of the from the
ancient birth of the odometer or possible birth of the
odometer in some of these instances, because it seems it's
kind of like we have the wheel turning on the road,
and then it's a question of could we put that
wheel to use, Like the wheel is already in a
sense marking the distance in its revolution, and in that
(22:40):
it's kind of like the heavens. It's like the sun,
it's like the moon, it's like the cyclical movements all
around us that mark the passage of time.
Speaker 2 (22:49):
Yeah, you just need to correlate something with like a
fixed number of teeth that you can count to those
pre existing revolutions, and then you take those teeth to
do some kind of war that will help you keep
the count, like dropping a bean in a bucket or
advancing a dial on a fixed face that has a
number printed on it.
Speaker 1 (23:07):
Yeah, and you can imagine that in the ancent mindset,
like you would have realized if we could harness this,
like this is better than counting your steps. There's a
regularity to this that would be harder to achieve through
other means.
Speaker 2 (23:23):
Totally.
Speaker 1 (23:23):
So.
Speaker 2 (23:24):
Vitruvius describes a machine roughly like that. Hero later describes
a similar machine, but there are some interesting differences in
how the two authors present their explication. For example, Vitruvius
describes his odometer with fixed dimensions. The wheel is four
Roman feet in diameter, the circumference is approximately twelve point
(23:45):
five feet, and so forth. And here I want to
read a passage from roby quote. Rather than providing a
mathematical formula whereby the odometer could be adapted to any
desirable or available wheel size, as Hero does for his
own description of an odomo, Vitruvius avoids formulas and geometrical
language by specifying the wheel diameter and circumference as fixed numbers.
(24:08):
That is to say, the version of the odometer he
gives his reader is presented as the exact device transmitted
from his quote predecessors, not a jumping off point for
experimentation with the type of device. And she goes on
to explain this as typical of the difference between Latin
language technical literature from this period and Hellenistic technical literature.
(24:32):
Works in Latin tended to be exact descriptions of existing devices,
rather than demonstrations of principles and scalable instructions for building
new machines. The latter. The scalable instructions and explication of
principles is more like what Hero of Alexandria presents. Instead
of having fixed dimensions, his explanation is about how to
(24:55):
apply the idea of an odometer to different scales and use,
with the numerical figures being ratios rather than measurements. So
Hero's goal was to represent these relationships between the different
sizes of the wheels and the connected gears, and then
to read one final passage from Roby quote. Hero's description
(25:16):
allows mechanical flexibility as well. He suggests how to extend
the number of cogs in the odometer, which can radically
enhance its measuring capacity. On the other hand, he notes
that it is pointless to make an odometer that measures
a greater distance than its vehicle could cover in a
single day, as it is easiest to just start the
count over each morning, which I like. That's very practical,
(25:40):
but it also flags an interesting difference here. They're just
different assumptions about the reader the text. In a more
Hellenistic tradition, or as Hero does, it might be geared
more toward a select audience of highly educated polymaths who
would be expected to take the engineering principle and then
vary it to their needs, whereas the Latin Roman tradition
(26:03):
is describing an exact device in a more accessible way
that's easy to replicate but offers less deep understanding and flexibility.
But I wanted to come back to a kind of
a lingering question about Alexander's bemtists, whether they used a
mechanical odometer or not, And the question is which is
(26:23):
actually more accurate. You might assume a mechanical odometer is
more accurate, but I've read some arguments that actually human
pacers would be less prone to error over a long
distance than a primitive mechanical device would be. Now, obviously
the best possible scenario would be like to have the
odometer on a modern car. You know, something that is
(26:46):
highly accurate, very well calibrated, a highly accurate modern device
that's going to give you the best reading. But obviously
something built in the fourth century BCE would have significant
enough inaccuracy in its measurements that this would cause problems
over great distances. And so the idea is that any
(27:06):
inaccurate measurement in a mechanical device would just build up
and up over many, many miles on a great journey,
like if the circumference of your wheel is slightly too
long over thousands of miles, it will start to significantly
underestimate the distance traveled. Meanwhile, I think the idea at
least is that human biobemitists literally counting their steps will
(27:28):
also have inaccuracy, maybe inaccuracy relative to some reference length
of a single pace, but that inaccuracy will go both ways.
Steps that are too long and then steps that are
too short, and those will average out over time. That's
the argument at least, and I see the logic here,
and I admit that I'm not a genius at statistics,
(27:49):
so I could be wrong. But my reaction is that
I think this could also be mistaken because it would
tend to assume that the human pacers inaccuracy will not
be consistently biased, either above or below whatever the reference
pace length being used is. So I think this logic
might work if you had like a group of a
(28:09):
thousand people walking, and then you had all of them
count their steps, and then you averaged all of those together.
But if it was just a single person, I would
tend to think that their personal count might be biased
more in one direction or another. They would just tend
to have longer than average or shorter than average steps,
and that even a pretty primitive machine would be better.
(28:32):
But I don't know.
Speaker 1 (28:33):
That's fascinating. Yeah, I don't quite know what to make it, because, yeah,
I can see what they're getting at with the idea
that some sort of a basic mechanical flaw in an
ancient odometer device that you would just consistently get the
wrong number, and then that would build up over time,
and then yeah, when it comes to the actual steps
(28:55):
and the counting of those steps by an individual or individuals,
you'd have, you know, a little in one direction, a
little another direction, but it would sort of even out. Yeah,
it's fascinating to think about.
Speaker 2 (29:06):
I mean, I think it would be more likely to
even out if you were talking about a group of people,
like a large group of people all average together. Yeah,
I don't know if that'd be the case for a
single person. Anyway, whether or not they were using mechanical odometers,
ancientdematists did a not at all bad job of measuring
different distances between milestones between cities, and it's possible they
(29:30):
were helped in this task by devices like the ones
described by Vitruvius and Hero. But ultimately, I think we
don't know for sure if they use these devices or not,
and if they did, we don't know for sure who
invented these ancient odometers. It's one of those questions, you know,
there are many inventions where we just don't know where
(29:50):
they came from.
Speaker 1 (29:51):
I wonder too if it might have been a situation
where they use both where they're specialist in their field.
So perhaps like specialist in other fields, they're using more
than one method and then comparing the numbers and figuring
out some sort of more accurate measurement based on the two.
Speaker 2 (30:10):
Yeah, that could be. I don't know, But anyway, it's
really impressive that in what is like the third or
fourth century BCE, we've got people getting like really accurate
estimates of travel distances that are on the order of
hundreds of miles.
Speaker 1 (30:25):
Yeah, that's fascinating. Now, all this is going on in
the Greco Roman world, but as we've partially alluded to already,
there's also a history of the odometer in Chinese civilization
as well. In particular, the device in question is the
Lee recording drum carriage. Now, this is sometimes attributed as
(30:47):
an invention of Zhonghang, who lived seventy eight through one
thirty nine C. This is a Chinese polymath and court
astronomer in the Eastern Han dynasty. This is an individual
we've talked about before because there are a number of
different inventions that are attributed to him, one of which
was an early form of earthquake detection device. He had
(31:12):
an important role tending calendars and celestial events, aiding the emperor,
who of course ruled at the mandate of heaven, so,
you know, maintaining the balance between cosmos and civil life.
And this is a period of time that sometimes referred
to as the Golden Age of Chinese history, for centuries
of economic prosperity that saw the traffic of goods and
(31:34):
ideas across the Silk Road. He was an inventor, a poet,
and an early scientist. We have an older invention episode
about the earthquake detection device, and I was looking back
at some of our notes and I'm reminded that you
shared some of his poetry in that episode.
Speaker 2 (31:49):
Oh I don't remember that now. Was it good poetry?
Speaker 1 (31:52):
Oh? Yeah, yeah, it's good stuff. So he's credited with
a number of inventions innovations and achievements. He wrote a
treatise on mystical law the Cosmos, which included the theory
that the moon did not emit light, but reflected the
light of the sun. And he's also sometimes attributed as
the inventor of the Lee recording drum carriage, which again
(32:12):
is this odometer of sorts in Chinese history. Now it
is worth noting that kind of like the situation with
Hero and Archimedes, we have a very famous historical inventor here,
and he's attributed with a number of inventions. And so
I guess the question always lingers, is this an invention
(32:32):
that this individual invented? Is it something that they described
it is something? Is it something that just ends up
being attributed to them because the technology was known during
that time, or it's based on surviving records, etc.
Speaker 2 (32:47):
Yeah, exactly.
Speaker 1 (32:48):
So I ended up looking at some of the writings
of Joseph Needhaim on this. So. Needham lived nineteen hundred
through nineteen ninety five. He was a British biochemist, historian
of science and sonologists who wrote rather extensively on the
history of science and technology in China. His second wife
Lu gives him as a Chinese historian and biochemist, and
(33:10):
she was an important co researcher and co author in
his work. So we're talking multiple volumes that he wrote
during his lifetime. Very very much is life work. So
before we get to the carriage itself, I thought we
might stop to just consider roads in ancient China. So
Needham writes about roads in general in the short Science
(33:34):
and Civilization in China, and he points out that they
were quite comparable to the famous roads of the Romans.
Both empires had extensive road systems that served as a
means of logistically connecting their vast landholdings for travel and trade,
as well as playing an important part is just in
just communication through the empire. That's always something to keep
(33:56):
in mind that the road is also a lane for communication. Now,
both systems, the Roman and the Chinese, fell into long
periods of decay after the third century CE, he points out,
though he writes that while the collapse of Roman roads
had more of a fracturing effect in China, natural and
artificial waterways and some surviving mountain road systems enabled these
(34:19):
far reaching routes of communication to remain open. He also
points out something very interesting about these two independent systems
that this rather awe inspiring and I thought really nicely written,
and it also kind of ties into some of the
stuff we talked about in our previous episode about the
Roman military the Dethroned Emperor series quote. Should the Romans
(34:40):
have ever succeeded in conquering the Parthians and the Persians,
the two road systems might have met, perhaps somewhere west
of Shinjang, but this was not to be. The octopus
like arms expanded independently, each in a world of its own,
their builders, troubled only occasionally by the vaguest rumors of
(35:02):
another system too far away to matter. Zinjohn, by the way,
is in northwest China. That's where he's talking about here.
So yeah, this is such a I love this quote
because it's just imagining these two independent road systems like octopuses,
each doing their own thing, and if you know, world
history had gone a different way, there could have been
(35:24):
a situation where they met. It's crazy to think about,
like roads, I've often thought about. You know, you encounter
a road and where does that road end? You know
that basically goes It's not infinite, but it stretches on
for such a great distance, and to imagine these two
vast systems almost but not quite coming together. Yeah. Yeah,
(35:46):
it's kind of like I don't know if you've ever
played around with us to see like how far one
can drive on a given continent or unconnected continents, Like
at what point do things seem to break down? And
you would have to find some other route to connect
with another road. And I know when you get into
your Asia and Africa, like there are some pretty long
(36:07):
travels by road that are that are possible today. The
road is not going to be necessarily be great the
whole way, but you can do quite a lot. So anyway,
Needam points out that with the odometer or the way measures,
it's a pretty simple proposition from a mechanical standpoint. If
(36:30):
you have the wheel already, and you have row, and
you have if you have roads, you have wheels, then
all it is is quote a system of toothed wheels
constituting a reduction gear train so that one or more
pins revolve slowly, releasing catches at predetermined intervals, and in
the case of this invention, striking drums or gongs, so
(36:53):
the lee recording drum carriage. What is a lee. A
lee is the traditional Chinese measure of distance. Today's standard
eye at five hundred meters or one thousand, six d
and forty feet, but as with the mile in Western traditions,
historically there's some drift over exactly how far it is
supposed to be. But it's standardized today and would have
(37:14):
been standardized under different rules in different dynasties.
Speaker 2 (37:18):
Yeah, standardization of measures does seem like such an important
part of this too, because when I kept thinking about
the idea of a bimitist potentially trying to measure distance
with paces, I'm like, what is So you've got to
have something that's like a reference pace, right, if you
say something is x number of paces long, you've got
(37:39):
to either know how much your pace typically relates to
a standard measure like a mile, or you've got to
be using your paces as some kind of literal standard measure,
like people would know what that number meant.
Speaker 1 (37:53):
Yeah. Yeah, it's the history of measurements alone would be
something interesting to come back to, because, of course you
get into use of various parts of the human body
to form your base measurements, the creation of tools, and
certainly when you're getting into weights for goods and trade,
like some of our oldest data and oldest examples are
all related to that. But then when you start thinking
(38:15):
about these larger measurements, like the measurement between you know,
the fort in the frontier, that sort of thing, like
you can't just count, You can't just have someone go
out there with essentially a ruler and say, all right,
start measuring it off, like you've got to have some
other system. Yeah, yeah, all right. Sonam gets more into
the subject of the Lee measuring card here in Science
(38:39):
and Civilization in China, Volume for Physics and Physical Technology,
Part two Mechanical Engineering, and yeah, it gets into the
nature and origins of the Lee recording drum carriage. He
cites several sources and pose in Some of these are
sources that go into more detail, others just kind of
mention it in passing and points out that that many
(38:59):
of them of the carriage, yet they don't actually describe
the mechanism employed. In at least one case, it shows
up as a math problem. It's something along the lines
of if the Lee recording drum carriage were to travel
between this city and this city, how many times would
the gong sound? That sort of thing. The concept seems
to date back to the Han dynasty, and this is
(39:21):
where the attribution to Zunghing seems to come into play.
But when the carriage is described, it's generally described as
a carriage drawn by four horses, and it works based
on multiple cogged wheels, some vertical and some horizontal, you know,
all of course, much like the earlier example and the
Greco Roman traditions we were discussing, you know, it's tied
(39:42):
to the movement of the wheels. In the simpler version
of this carriage, it's said that there is a wooden
man in the carriage who is mechanically made to strike
a drum with the passage of each lee. So the
wheels are turning, the cogs are turned, learning there's a
mechanical wooden man inside who like a music box, he
(40:05):
is going to mechanically strike a drum. In this case,
every time one lee has.
Speaker 2 (40:10):
Passed, beat that. Vitruvius, you did not have a wooden man,
did you.
Speaker 1 (40:16):
Later, a more complex version is described as being two
stories in height, so it's a carriage that has two stories,
and each story has its own wooden figure. The lower
figure strikes a drum every lee, while the higher figure
rings a bell every ten lee.
Speaker 2 (40:33):
Okay, So one difference that occurs to me here is
this would still if it's keeping track of the distance
in an accurate way, but doing so by making a
sound instead of by say, accumulating pebbles or beads in
a container. It's something that you would to some extent
(40:54):
need to continuously keep track of as you're traveling, Like
it would still require effort, full engagement of the memory
by somebody doing the traveling, right.
Speaker 1 (41:04):
That's right. That's based on my reading here of Needham.
I don't think there's any indication that it was spitting
out like you know, balls or pebbles that could then
be counted later, or that was anyway recording how many
les it passed. It was just a you know, a
ringing of a bell or the striking of a drum
(41:25):
based on the intervals traveled.
Speaker 2 (41:26):
Which would still be useful, but would require more work
than or at least work spread out over a longer
period of time, rather than say like a single counting
activity in between travel segments.
Speaker 1 (41:39):
And in this we get into one of the big
questions about the lee recording drum carriage, and that is
was this a device that was at all originally intended
to measure distances? Or was it you? Or was it
more about music? Was it more about novelty? Was it
why was the technology employed so again this These writings
(42:02):
are typically revolving around the Han period or perhaps a
little earlier, but the lee measuring drum carriage was not
known as such until later, and Needham discusses that this
might mean that the invention was in fact more expressly
for musical performance rather than the measurement of distances. Again,
at least during this time period. It may have changed
(42:23):
later when someone realized, oh yeah, we can just count
how many strikes of the drum, we can count how
many rings of the bell, and then that's data that
could prove useful. But he stresses that you know, these
are still interconnect interconnected possibilities and if you're if you're asking, well,
why would they do that? Like why build a carriage
like this? And why does it remain something other than
(42:44):
just like a one time novelty, Like why is it
written about so much? And he points out that music,
of course, is often part of a procession, and he
stresses that quote carriages for musicians whether mechanized or not
survived in imperial processions through many subsequent dynasties. So the
idea here is that the mechanical version here develops from
(43:07):
non mechanical carriages with human musicians inside them. Imperial fleets
of vehicles, as he refers to them, would have likely
included palace officials and so forth, but also entertainers musicians.
So as everyone's traveling down the road, there's music, and
at some point someone says, hey, well, we could build
(43:28):
some gears. We could make a mechanical musical man inside
one of the carriages.
Speaker 2 (43:33):
Putting those flesh musicians out of the job.
Speaker 1 (43:35):
Well, I don't know if they'd be completely out of
the job, because you know, these the mechanical musicians can
only do so much here. But yeah, for a modern comparison,
we might think of a parade float as a counterpart
to something like this. It does sound a lot like
a parade float. It would have been, according to one account,
painted red and decorated with flowers and birds. It's described
(43:58):
as being escorted by eighteen men, and there would have
been a phoenix headed carriage pole on it. So this
was not clearly not something that was like a Google
Maps vehicle that was out there just to perform a task.
It also it said that it looked marvelous. It's a
joyous vehicle. And once more Needum stress is that we
(44:18):
don't know for sure if it was ever used by cartographers.
It's possible that later on cartographers may make use of
the data that could be provided by this, but we're
not sure. Interesting, so Needham points out that Hero's description
of thedometer did not claim it as a new invention.
He mentions Vitruvius and then mentions that after Hero Vitruvius,
(44:40):
the odometer appears in Western Europe during the fifteenth century.
So it's kind of not really on the Western European
radar for a long period of time, or doesn't seem
to be based on surviving histories, and then it re emerges.
Quote the pattern is therefore the same as that which
we have repeatedly met with i e. Greek antecedent paralleled
(45:01):
or followed by followed at short distance by Chinese developments
which continue throughout the medieval period, and then a reawakening
of the subject in Europe. So in this he's touching
on something that was kind of a career spanning question
for him is often referred to as the need Him question,
and that the question is basically why didn't China beat
(45:22):
Europe to the scientific revolution. He's been a fair amount
of his work thinking over this and looking to answers
and Chinese social institutions and more. Though as reading that,
synologist Nathan Sivin, who would have been I think at
times a collaborator with Needham, pointed out that, you know,
the whole thing is basically a why did an X
(45:43):
happen in history? Question, which, by some estimates is less
than a fruitful enterprise. You know, you get into all
sorts of complex butterfly winging, flapping concerns when you start
asking questions like that. They can be kind of nifty
head scratchers, but perhaps they are not the best exercise
for an historian. But at any rate, the need Hum question,
(46:04):
you see it mentioned a lot in discussions of the
history of Chinese science. Now, I do want to note
in reading about all this, I also read some material
for Needum about another interesting wheeled vehicle in Chinese history,
and that is the South Pointing chariot. But that's one
we're gonna have to come back to. But yeah, the
(46:24):
idea of a chariot with another mechanical man on it,
but this mechanical man always points south ominous.
Speaker 2 (46:31):
Okay.
Speaker 1 (46:33):
So we're not going to go through the exhaustive history
of the odometer in recent centuries, but I thought it
might be useful to point out a few different later
innovations that kind of bring us up to the modern odometer.
There's Pascal's calculator. This would have been an invention or
(46:53):
an innovation by Blaise Pascal. This was sixteen forty five,
not in a dometer per se, but it was a
computation mechanism that entailed rotating toothed gears, and much like
a modern odometer, one complete cycle of one gear caused
the movement of the next gear.
Speaker 2 (47:10):
Okay, So this would have been taking the same principle
by which the ancient odometer worked, but applying it to
general calculation rather than just the movement of a vehicle wheel.
Speaker 1 (47:21):
Right now, in the late sixteen hundreds early seventeen hundreds,
we also see Thomas Savory's nautical odometer. Savory's most famous
invention was the steam engine, but he also devised a
nautical odometer. I actually couldn't find out much about this,
so I don't know. I'm I have to come back
to this one in the future, but because I was
curious on how exactly it would have functioned. Oh interesting, Yeah,
(47:42):
supposedly there was a patent, so it seems like I
should be able to find that patent somewhere. So I
don't know, I'll have to come back to that one.
But this is a fun part because our old friend
Ben Franklin also enters the fray here when it comes
to the odometer. He's come up in more than one
invention come resition, I believe.
Speaker 2 (48:01):
So what was his take?
Speaker 1 (48:03):
So in seventeen seventy five, he was serving as Postmaster
General for the British Previously he had been postmaster of Philadelphia,
and he wanted more data on the shortest routes for
mail delivery. So he basically devised a simple odometer to
attach to his own carriage. And this will for this
(48:23):
reason you'll sometime see, especially some online sources, saying Ben
Franklin invented the odometer. No, it's not accurate in the
least to say Ben Franklin invented the odometer. You could
say he invented unodometer. He certainly whipped one up on
the fly. Here. It seems so every four hundred revolutions
it would register a mile, and the results were apparently
(48:45):
pretty accurate based on what I was reading here. So
at any rate, he was able to use the data
to figure out which route was best for mail delivery.
Speaker 2 (48:54):
Now, one thing I know I saw reference to on
the internet and I didn't know what to make of
this was the idea of a a Mormon odometer.
Speaker 1 (49:02):
Yeah, this was one that that came up for me
as well. The rohdometer from Clayton and Pratt. This would
have been eighteen forty seven. They were pioneers of the
Church of Jesus Christ of Latter day Saints, and they
apparently crafted a simple odometer to measure how far a
wagon train had traveled. So that's it's interesting again. You're
(49:24):
getting into this area where it sounds like people would
find themselves in situations where they could really use an odometer.
And since the knowledge was known, you could create one.
You couldn't go to the store and buy one, but
the principles were out there. The principles were part of
the technological canon, so you could draw on that and
make yourself a functional odometer. In eighteen ninety five Curtis
(49:49):
h Veder came up with a bicycle mounted odometer, the cyclometer,
and then in nineteen oh three we have the Warner autometer,
which I think like the average versions of this, this
was like an actual product. It was a combined odometer, speedometer,
and clock, but it made use of magnetism as opposed
to just pure gear work. So like those are some
(50:11):
of the big more big innovations in the odometer in
recent centuries. And yeah, today the odometer again is something
we tend to just take for granted or we don't
even read it. It just sort of clicks by there
and maybe we check in on it every you know, however,
many thousands of miles, I guess it varies. Some people
are probably more into keeping a close eye in their odometer,
(50:32):
or you have to for work. Obviously.
Speaker 2 (50:34):
I think about seeing those surveyors who have the wheel,
they use the surveyors wheel.
Speaker 1 (50:39):
The surveyor's wheel. Of course I didn't think about that.
That's an obvious innovation to compare to some of these
discussions of the odometer, like harnessing the power of the
wheel for measurement. All right, Well, we're going to go
and close it out here, but we'd love to hear
from everyone out there. Perhaps you have particular thoughts about
the odometer, it's ancient history, it's recent history, tree, or
(51:01):
our modern use of the technology. Write in We would
love to hear from you. As a reminder, our core
episodes of Stuff to Blow Your Mind published on Tuesdays
and Thursdays, and the Stuff to Blow your Mind podcast
feed on Mondays, we do listener mail. On Wednesdays we
do a short form artifact or monster fact, and on
Fridays we do Weird House Cinema. That's our time to
set aside most serious concerns and just talk about the
(51:22):
strange film huge.
Speaker 2 (51:23):
Thanks to our excellent audio producer Seth Nicholas Johnson. If
you would like to get in touch with us with
feedback on this episode or any other, to suggest a
topic for the future, or just to say hello, you
can email us at contact at stuff to Blow your
Mind dot com.
Speaker 3 (51:38):
Stuff to Blow Your Mind is production of iHeartRadio. For
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