Welcome to Stuff to Blow Your Mind production of My Heart Radio. Hey you welcome to Stuff to Blow Your Mind. My name is Robert Lamb and I'm Joe McCormick. Today Unstuffed to Blow your Mind, we have another invention themed episode for you. We're gonna be talking about something that might initially seem frightfully dull or at least very commonplace, and that is the odometer. I mentioned this to Rachel earlier and she was like, oh, yes, the device that measures odors. Yes or odo's. If you were to read the word wrong, you might think it says autometer, um, but it's yes, the odometer. So everyone other you probably know this device best is the little counter in your vehicle, the 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 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 and 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. It's something that turns a vehicle into a tool from measurement, 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 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. Yeah, we've talked before about the some of the 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, what is the distance from one place to another, from border to border from port to capital, from frontier to ford and sofa 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 an odometer is, and knowing that an odometer has uh 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, uh 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 at its history both in the east and in the west. Now, I think it's worth thinking at least just a little bit about maps and cartography here, because it's easy for 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, Uh. 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 many miles and inches or something to that effect. Oh, once you get into D and D, though, I feel like it's often very loosey goosey about travel distances. Oh yeah, and um and as a when I am dungeon mastering, I 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's just it's however long it takes to get there. But any well, my experiences, you want to you want to take a queue from the d M 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? 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 in the other, and thinking about the role of maps in the ancient world. I turned to one of my my favorite go to text for a lot of this sort of thing, Brian Fagan's The seventy Grade Inventions of the Ancient World, And there's a there's several different chapters in there, the deal with measures and maps. Uh and of Fagin 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 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. Yeah, that makes sense, navigating by landmarks. Yeah, and so the maps would reflect that. Another thing they point out is that while local maps in the ancient world we're one thing, as we're specialized maps, broader maps of the world or region, we're 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 uh, this is one quote from the book I thought was rather telling quote between them rulers, generals, sailors, and traders evidently all but ignored the practical assistance that maps could afford them. That's surprising. Yeah, I mean hindsight twenty but uh, yeah, it's interesting to look back and think about what benefits this broader approach to maps general purpose maps, etcetera. Could have afforded them, So I think all that's worth keeping in mind as we proceed here. None of this is to say peoples during these eras were not concerned with precise distances, but the relationship with exact maps wasn't quite the same as what we have now now. 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 very interesting puzzle that emerges if you look at a geography chapter of The Natural History by by our old friend Plenty of the Elder. Here I'll be referring to the Bostock and Riley translation for those not familiar. Plenty of the Elder was a first century Roman military commander and author, and the Natural History is 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 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, sees to ounds, havens, mountains, rivers, distances, 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 a hundred kingdoms, dozens of rivers, 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. We will follow the track of Alexander the Great. Diagonitis and Biton, 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 Ptarthians, the distance is the number of miles, which we have already stated and he mentioned a number earlier, and then he goes on and that from thence to Alexandria of the ri I, which city was founded by the same king, the distance is five hundred and seventy five miles, and from thence to Prophesia, the city of the drag Ni, one hundred and ninety nine miles. And from here he just goes on and on, listing distances. It's this many miles to the next city, and this many miles to the next city. Uh. So he attributes all of these numbers, all of these distances and miles that he comes up with for this path leading into India to these two figures, Diagnetis and Biton. Who were these guys well, they were known as Bimatists, coming from the Greek word meaning step or pace. I looked up Bimatists in the Oxford Handbook of Classics, and the entry does identify them as the the surveyors essentially of Alexander the Great Uh and names a few other ones. In addition to the two already mentioned Byton and Diagnetus. It also names uh Philonides of Crete, who it says in a side note, was a celebrated distance runner, and the entry also notes that the two figures who worked for Alexander, Byton and Diagnetus, 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 Bemetists published their observations in monographs termed stath moy or Stages, 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 Eratas the Knees with the framework for his geography of Asia. Aretas the Nees, you might recall, was an really figure, 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 sundials. Basically, yeah, So, how did the Bematists actually 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 the distances recorded by bematists such as Biton 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 a 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 in nineteen seventy eight. And explaining a table in his book of the bimatists different estimates of the distances between cities on this route, ingles rights quote the overall accuracy of the bimatists measurements should be apparent. The minor discrepancies of distance parentheses only one point three percent from herat to begrum, 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 bimatists used a sophisticated mechanical device for measuring distances, undoubtedly an odometer, such as described by Heron of Alexandria. So there's a clue. Uh Ingles here says, Look, the distance is given by these these people who worked for Alexander the Great and other immotists of the era. They're just too accurate. They're 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 described later by Heron of Alexandria. Now, this idea that they may have simply been walking, on one hand, I can't help but think of the Monty Python ministry of silly walks and imagine like a specific, ridiculous but regular date that they're using, and and if they were super focused on their steps and counting their steps, maybe that would explain why they're reports of flora and fauna are so outrageous. They're like, well, I was it was. It was three thousand, eight hundred and seventies 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 the step count right. I mean, descriptions of local flora, fauna, and people's of the world are notably hilarious throughout all kinds of ancient texts, including Plenty himself. He loves to talk about people who had like eyes in their stomachs and stuff. Yeah. I keep hoping one day I'll come across a passage in Plenty where he mentions people who have crab clause. I haven't found that yet. Oh, I have to have to look into that, I mean, because you mentioned it's it's of course not just Plenty in his writings and travelers that he's sourcing, and we we've discussed similar things in Chinese traditions as well, So there have to be some crab claude individuals out there somewhere. But okay, sorry to 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 Iron, 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 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 Yala pile, which is a type of early steam engine converting the power of steam into rotational energy. Basically it works, but you've got a big cauldron this full of water, and then you put a fire 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 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 the as it gets hotter and hotter and the cauldron and the steam pressure builds up, it spins the sphere faster and faster. Yeah, there are a lot of images of this, as I recall, I remember seeing a cool woodcut of this, I think at one point um but it has a look of of a novelty of a device that's that's illustrating the principle here, but but of course not putting it to the sort of work that later UH steam engines would. For sure. Yes, and though the e Allo pile is often associated with UH, with Hero, I think this is something that he very likely did not actually invent. It was just something he described that already existed. UM. But we have talked about other machines possibly invented by Hero in previous episodes. One that I remember is the Hero of alexandrias In 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 think you'd put a five drachma or five drama 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 was simply describing a device that had already been invented by two Cbs of Alexandria in the third century BC. So, as with 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. Anyway, I found multiple references to Hero either inventing or describing an odometer, as 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, this machine he describes in the diopter again, the Hero is first century CE. A couple of caveats. One is that he Hero 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 BC, so century before Hero, also describes an odometer, uh, though in a slightly different way. I'll get into the differences in a minute. But even Vitruvius does not claim to have 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 bimatists must have had a device like Heroes. The problem here is that hero of Alexandria and Vitruvius both lived along after the conquest of Alexander the Great. So if it's true as Ingles suggests that these bimatists 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 Vitruvious. Is not something that hero or Vitruvious and vented. Now. An interesting source I found on on these two device descriptions is a book called Technical Exprassis 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. Courtney Roby is a professor of classics at Cornell and in this book, this is in 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 the earlier mentioned by Vitruvius comes in a book 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 what evidence there would be for this, so I'm not sure how strong that suggestion is. Maybe it's just kind of like, oh, Archimedes, he invented stuff, and maybe it's him. Yeah, I think some sometimes we see in different traditions we have these these noted inventors, noted minds, and they kind of become mythic magnets for various ideas and inventions. But there might be some good reasons for think of our comedies. I just don't know if there is. I did not turn it up than 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 your basic point of contact with the Earth 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 h 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 about twelve point five six. So when Vitrivius 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 advance a cog wheel by one cog position, you know, one tooth advances and the cog has the cog wheel has a fixed number of teeth, meaning that it will make a full 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 the little pebbles or beads or beans are to know how many miles you've gone. And I want to make a note that 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 Antikithera mechanism. 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 is something that creates mechanical advantage, and it certainly does do that, but a gear can also manage ratios between numbers, like a gear can do math for you, and that's what it's doing in the case of this odometer. Yeah, I love these these examples of them from the ancient birth of the odometer or possible birth of the odometer, and some of these these instances, because it seems it's'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 and in that it's kind of like the heavens. It's like the sun. It's like the moon, it's like the the cyclical movements all around us that mark the passage of time. 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 work that will help you keep the count, like dropping a bean in a bucket, or advancing a dial to on a fixed face that has a number printed on it. Yeah, and it and it. You can imagine that into the in the ancent minds like you would have realized if we could harness this, like this is better than than than counting your steps. There's a regularity to this that would be harder to achieve through other means. Totally so so. 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 dodometer with fixed dimensions. The wheel is four Roman feet in diameter, the circumference is approximately twelve point 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 odometer, Vitruvious avoids formulas and geometrical language by specifying the wheel diameter and circumference as fixed numbers. 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. Works in Latin tended to be exact descriptions of existing devices rather than demonstrations of principles and scalable instructions for building new machines. Uh the ladder the you know, 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 apply the idea of an odometer to different scales and uses. 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 Robi quote. Heroes description 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 warning, which I lay. That's very practical, but it also it flags an interesting difference here. They're just different assumptions about the reader uh the text. In a more Hellenistic tradition, or as 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 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 bematists, whether they used a mechanical odometer or not. And the question is which is 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 highly accurate, very well calibrated, a highly accurate modern device, uh, that that's going to give you the best reading. But obviously something built in the fourth century b c. Would have significant enough inaccuracy and its measurements that this would cause problems over great distances. And so the idea is that any 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 biobmtists literally counting their steps will 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 I'm not a genius at statistics, 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 past length being used is. Uh So, I think this logic might work if you had like a group of a 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. But I don't know. That's fascinating, Yeah, I don't. I don't know what to make it because yeah, I can. 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 when it comes to the actual steps and the counting of those steps by an individual or individuals, you'd have, you know, a little, a little in one direction, a little another direction, but it would sort of even out. Yeah, that's that's fascinating to think about. 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, ancient dematists did a not at all bad job of measuring different distances between milestones between cities, and it's possible they were helped in this task by devices like the ones described by Vitruvious 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 it's one of those questions. You know, there are many inventions where we just don't know where they came from. I wonder too if it might have been a situation where they use both where where their specialist in their field. So perhaps, like specialists 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. Yeah, that could be. I don't know. But anyway, it's really impressive that in the what it's like the third or fourth century b c. We've got people getting like really accurate estimates of of travel distances that are on the order of hundreds of miles. Yeah, that's fascinating. Now, all of this is going on in the Greco Roman world, but as we've partially alluded to already, there's 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 an invention of Zongheng, who lived at seventy eight through one c E. This is a Chinese polymath and court astronomer in the Eastern Han dynasty. Uh. 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. Uh. He had an important role tending calendars and celestial events, aiding the Emperor Um, 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's all the traffic of goods and ideas across the Silk Road. He was an inventor, a poe it in 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 that you shared some of his poetry in that episode. Oh I don't remember that now. Was it good poetry? Oh? Yeah, yeah, that's good stuff. Um. So he's credited with a number of inventions, innovations, and achievements. He wrote a treatise on the Mystical Laws of 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 is this um uh, this this odometer of sorts in Chinese history. Now it is worth noting that 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 that this individual invented? Is it something that they described it something? Is it's something that just ends up being attributed to them because the technology was known during that time, or it's based on surviving records, etcetera. Yeah, exactly. So I ended up looking at some of the writings of Joseph need Him on this. So Needham lived. He was a British biochemist, historian of science and sinologists who wrote rather extensively on the history of science and technology in China. His second wife, lu gives him was a Chinese historian and biochemist, and 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 his life work. So before we get to the carriage itself, I thought we might stop to just consider Rhodes in ancient China. So Needham writes about Rhodes in general in the short Science 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 land holdings for travel and trade as well as you know, playing an important part is just in just communication through the empire. That's always something to keep in mind, uh, 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 see 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 far reaching routes of communication to remain open. He also points out something very interesting about these two independent systems, that it's this rather on 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 that the Dethrone Emperor series quote. Should the Romans have ever succeeded in conquering the Parthians and the Persians, the two road systems might have met, perhaps somewhere west of shin Jiang, 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 another system too far away to matter. It's in John, 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 a imagining these two independent road systems, like like like octopuses, Uh, each doing their own thing. And if you know, world history had gone a different way, there could have been a situation where they met. Uh. It's it's crazy to think about, like 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 uh, you can it stretches on for such a great distance. And to imagine these two vast systems um almost but not quite coming together. Yeah, it's kind of like I don't know if if you've ever played around with this to to see like how far one can drive on a given continent or on connected 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 Eurasia and Africa, like there are some pretty long travels by road that are that are possible today. The road is not going to be necessarily to be great the whole way, but you can do quite a lot thank so. Anyway, Needham points out that with the odometer or the way measure, it's it's a pretty simple proposition from a mechanical standpoint. If 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 revolved slowly, releasing catches at predetermined intervals, and in the case of this invention, striking drums or gongs, so the lee recording drum carriage. What is Alie Alie is the traditional Chinese measure of distance today, standardized at five meters or one thousand sixty feet, but as with a mile and Western traditions, historically there's some drift over exactly how far it is supposed to be. But it's standardized today and would have been standardized under different rules and different dynasties. Yes, standardization of measures does seem like such an important part of this too, because I when I kept thinking about the idea of 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 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. Yeah, yeah, it's yeah. The the history of 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 uh to to form your base measurements, UH, the creation of tools and UH 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 about these larger measurements, like the measurement between you know, the fourth in the frontier, that sort of thing, like you 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 gotta have some other system. Yeah, yeah, alright, So Needa gets more into into the subject of the lea the Lee measuring art here in Science and Civilization in China, Volume for Physics and Physical Technology, Part two, Mechanical Engineering, Um, and yeah, it gets into the nature and origins of the Lee recording drum carriage. He cites several sources and post in some of these resources that go into more detail. Others just kind of mentioned it in passing and points out that that many of the mentions of the carriage, yeah, they don't actually describe the mechanism employed. In at least one case, it shows up as a math problem. It's 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 u sound that sort of thing. The concept seems to date back to the Hun dynasty, and this is where the attribution to zong Hang 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 in the Greco Roman traditions we were discussing, you know, it's tied to the movement of the wheels. In the simpler version of this um 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 turning, there's a mechanical wooden man inside who like like a music box, he is going to mechanically strike a drum in this case, every time one lee has passed. Beat that vitruvious. You did not have a wooden man, did you. Later, a more complex version is described as being two stories in heights, So 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 le 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 uh, pebbles or beads in a container. It's something that you would to some extent need to continuously keep track of as you're traveling, Like it would still require effortful engagement of the memory by somebody doing the traveling, right, That's right. That's based on my reading here of need him. I don't think there's any indication that it was spitting out like you know, balls or or or or pebbles that could then be counted later, or there was anyway recording how many leaves it passed. It was just a you know, a ringing of a bell or the striking of a drum based on the intervals traveled, 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. 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 was it? Why was the technology employed? So again this was this? These writings 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 need Him 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 may have changed 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 interconnected, interconnected possibilities, um. 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 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 uh here develops from 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, what we could We could build some gears. We could make a mechanical musical man inside one of the carriages, putting those flesh musicians out of the job. Well, I don't know if they've become cletely out of the job, because you know that these these mechanical musicians can only do so much here. But but yeah, for for a modern comparison, we might think of of a parade float as a as a counterpart is 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. It's described as being escorted by eighteen men. Uh, 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, Needham stresses that we don't know for sure if it was ever used by cartographers. Uh. It's possible that that later on photographers may make use of the data that could be provided by this, but we're not sure. Interesting, so Needham points out that heroes description of the podometer did not claim it as a new invention. He mentions the truvious and then mentions that after hero Vitruvius, the odometer appears in Western Europe during the fifteenth century, so it's 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 antecedents paralleled 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 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. Uh though, as as of reading, the psychologist Nathan Siven, who would have been I think at times of liberator with Needham, pointed out that, you know, the whole thing is basically a why did an X happen? In history question, which by some estimates is less than a fruitful enterprise. You know, you get into all sorts of complex butterfly wing 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 Needham question, you see it mentioned a lot in discussions of of the history of Chinese science. Now, I do want to note in reading about all this I also read as 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 idea of a chariot with another mechanical man on it, but this mechanical man always points south omous. Okay. So we're not gonna We're not gonna go through the exhaustive history of the of the odometer in 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. Um, there's Pascal's calculator. This would have been an invention or an innovation by Blaze Pascal. Uh. This was five not an adometer 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. 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. Right now, in the late sixteen early seventeen hundreds, we also see Thomas Savory's nautical odometer. Uh. Savories most famous invention was the steam engine, but he also devised a nautical adometer. I actually couldn't find out much about this, so I don't know. I'm gonna have to come back to this one in a few sure, but because I was curious on how exactly it would have functioned. Interesting. Yeah, supposedly there was a patent, so it seems like I should be able to find that patent somewhere. So I don't know, I 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 conversation, I believe. So what what was his take? So? In 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 UH, and this will for this reason you'll sometimes 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 on odometer. He certainly would one up on the fly here. It seems so every four revolutions it would register a mile and the results were apparently pretty accurate based on what I was reading here. So at any rate, he was able to to to use the data, uh, to figure out which route was best for male delivery. 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 Mormon odometer. Yeah, this was one that, Yeah, that came up for me as well. The rhodometer from Clayton and Pratt. Uh. 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. Um. So that's it's interesting again. It's we're 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 was known, you could create one. You couldn't go to the store and buy one, but the principles route there. The principles were part of of of of the technological canon, so you could draw on that and make yourself a functional odometer. In e Curtis age Vter came up with a bicycle mounted odometer, the cyclometer, and then in three we have the Warner autometer, which I think, like the advertised versions of this, this was like an actual product. It was a combined odometer, spedometer, and clock, but it made use of magnetism as opposed to just pure gear work. Uh So, like those are some of the big more big innovations in the odometer in recent centuries. And uh 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 at vary some people were probably more more into keeping a close eye in their odometer, or you have to for work obviously. I think about seeing those surveyors who have the wheel they use the surveyors the surveyor's wheel. Of course, I didn't think about that. That that's an obvious um innovation to compare to some of these discussions of the odometer, like harnessing the power of the wheel from measurement. All right, well, we're gonna 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, or or you know, our modern use of the technology right in we would love to hear from you. 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