WEBVTT - The Invention of the Odometer 0:00:03.040 --> 0:00:05.360 Welcome to Stuff to Blow Your Mind production of My 0:00:05.480 --> 0:00:14.720 Heart Radio. Hey you welcome to Stuff to Blow Your Mind. 0:00:14.880 --> 0:00:18.320 My name is Robert Lamb and I'm Joe McCormick. Today 0:00:18.680 --> 0:00:21.120 Unstuffed to Blow your Mind, we have another invention themed 0:00:21.120 --> 0:00:24.400 episode for you. We're gonna be talking about something that 0:00:24.560 --> 0:00:28.400 might initially seem frightfully dull or at least very commonplace, 0:00:28.480 --> 0:00:31.480 and that is the odometer. I mentioned this to Rachel 0:00:31.520 --> 0:00:34.720 earlier and she was like, oh, yes, the device that 0:00:34.800 --> 0:00:39.760 measures odors. Yes or odo's. If you were to read 0:00:39.800 --> 0:00:42.680 the word wrong, you might think it says autometer, um, 0:00:42.720 --> 0:00:45.920 but it's yes, the odometer. So everyone other you probably 0:00:45.960 --> 0:00:49.520 know this device best is the little counter in your vehicle, 0:00:49.560 --> 0:00:52.280 the records how far you've driven. And I think we 0:00:52.360 --> 0:00:56.160 tend to think of this invention mostly as a self 0:00:56.200 --> 0:00:58.880 centered device. It tells us how far we've driven on 0:00:58.960 --> 0:01:02.040 our trip, how many miles or kilometers we've racked up 0:01:02.080 --> 0:01:05.280 on our vehicle. But you know, there's another way of 0:01:05.280 --> 0:01:07.600 looking at the odometer, and this, certainly this is something 0:01:07.640 --> 0:01:11.240 that plays into and into the history of the invention 0:01:11.360 --> 0:01:14.720 and also our attempts to understand its place in the 0:01:14.760 --> 0:01:18.280 ancient world. Is that an odometer can also be a 0:01:18.319 --> 0:01:22.039 method of determining distances on given routes. It's something that 0:01:22.120 --> 0:01:26.480 turns a vehicle into a tool from measurement, right, So 0:01:26.600 --> 0:01:29.920 it's it gives you information that would be useful to 0:01:30.000 --> 0:01:32.560 other people, because I mean, in the ancient world, you 0:01:32.600 --> 0:01:35.920 don't have Google Maps or anything. You might know that 0:01:35.959 --> 0:01:37.959 there are two cities, and you might know that you 0:01:38.000 --> 0:01:40.320 get from one of them to the other by following 0:01:40.319 --> 0:01:43.000 the road to the west, but you might not know 0:01:43.160 --> 0:01:45.240 how long it's going to take you to get from 0:01:45.240 --> 0:01:47.560 one to the other. So it would be very useful 0:01:47.600 --> 0:01:50.600 if you actually had some standard distance measurements that would 0:01:50.600 --> 0:01:52.800 allow you to estimate the length of the journey and 0:01:52.800 --> 0:01:54.680 to know how much you need to pack for the 0:01:54.760 --> 0:01:59.200 journey and so forth. Yeah, we've talked before about the 0:01:59.280 --> 0:02:02.040 some of the the important things that make up an 0:02:02.040 --> 0:02:05.040 empire and make an empire or a kingdom function, and 0:02:05.040 --> 0:02:09.160 there are things like standardized measurements, of course, and standardized currency. 0:02:09.960 --> 0:02:13.760 But another thing that would be useful is indeed, like 0:02:13.800 --> 0:02:15.720 you say, to know how long it takes to get 0:02:15.760 --> 0:02:18.760 from one place to another, what is the distance from 0:02:18.760 --> 0:02:22.640 one place to another, from border to border from port 0:02:22.720 --> 0:02:26.280 to capital, from frontier to ford and sofa forth. And 0:02:26.360 --> 0:02:27.880 this is the kind of thing that would of course 0:02:27.880 --> 0:02:31.040 be important for warfare, but also for trade and just 0:02:31.160 --> 0:02:35.839 general management of a given territory. So on one hand, 0:02:35.880 --> 0:02:38.200 you can imagine this situation, and you can and you 0:02:38.240 --> 0:02:41.240 can think about what an odometer is, and knowing that 0:02:41.480 --> 0:02:44.320 an odometer has uh some of its history in the 0:02:44.360 --> 0:02:46.440 ancient world, you might think, well, this is the this 0:02:46.480 --> 0:02:48.400 is the route we take to get to the invention. 0:02:48.480 --> 0:02:51.240 This is the necessity, uh that is the mother of 0:02:51.280 --> 0:02:54.400 this invention. But this doesn't necessarily seem to be the case, 0:02:54.560 --> 0:02:57.880 as we'll discuss, as we look at at its history 0:02:57.960 --> 0:03:00.440 both in the east and in the west. Now, I 0:03:00.480 --> 0:03:02.480 think it's worth thinking at least just a little bit 0:03:02.760 --> 0:03:06.160 about maps and cartography here, because it's easy for for 0:03:06.200 --> 0:03:07.640 the mind to go there, like I need to know 0:03:07.680 --> 0:03:10.639 the exact distance between X and Y because I want 0:03:10.680 --> 0:03:14.079 an accurate map, right, Uh. To kind of go hand 0:03:14.120 --> 0:03:16.480 in hand when we think about maps today, Like even 0:03:16.520 --> 0:03:19.760 if I'm looking through a Dungeons and Dragons book, I 0:03:19.840 --> 0:03:22.000 have a map of some sort of fantastic region, and 0:03:22.000 --> 0:03:24.600 then I have a little indicator to tell me exactly 0:03:24.639 --> 0:03:28.079 how how many miles and inches or something to that effect. Oh, 0:03:28.200 --> 0:03:30.120 once you get into D and D, though, I feel 0:03:30.160 --> 0:03:34.920 like it's often very loosey goosey about travel distances. Oh yeah, 0:03:35.160 --> 0:03:39.360 and um and as a when I am dungeon mastering, 0:03:39.440 --> 0:03:40.920 I I am also I hate it when there's like 0:03:40.960 --> 0:03:44.320 a really specific question about distances, like, well, is it 0:03:44.400 --> 0:03:45.960 is it one mile or two mile? It's like, I 0:03:45.960 --> 0:03:47.640 don't know, it's just it's however long it takes to 0:03:47.680 --> 0:03:51.320 get there. But any well, my experiences, you want to 0:03:51.360 --> 0:03:53.280 you want to take a queue from the d M 0:03:53.440 --> 0:03:56.440 basically like, is this a journey where things will happen 0:03:56.520 --> 0:03:58.640 on the journey or a journey where we will just 0:03:58.720 --> 0:04:03.040 magically arrive at the destination? Yes, sometimes the magic is 0:04:03.080 --> 0:04:05.680 in the journey, but sometimes it most definitely is not. 0:04:06.320 --> 0:04:09.800 So thinking about this the situation about figuring out knowing 0:04:09.840 --> 0:04:12.520 what the distances are between one place in the other, 0:04:12.600 --> 0:04:15.440 and thinking about the role of maps in the ancient world. 0:04:15.880 --> 0:04:18.320 I turned to one of my my favorite go to 0:04:18.440 --> 0:04:19.919 text for a lot of this sort of thing, Brian 0:04:19.920 --> 0:04:22.960 Fagan's The seventy Grade Inventions of the Ancient World, And 0:04:23.080 --> 0:04:25.880 there's a there's several different chapters in there, the deal 0:04:25.960 --> 0:04:30.320 with measures and maps. Uh and of Fagin and his 0:04:30.360 --> 0:04:32.280 co authors point out, I think a few important things 0:04:32.320 --> 0:04:35.960 about ancient maps that we might want to have in 0:04:36.000 --> 0:04:38.840 our head as we proceed. So, first of all, they 0:04:38.839 --> 0:04:41.679 point out, the Chinese maps of old were more about 0:04:41.760 --> 0:04:45.200 landscape features. So the journey from X to Y is 0:04:45.240 --> 0:04:49.040 more about the details of the landscape and the markers 0:04:49.080 --> 0:04:51.640 that are passed on the way. Yeah, that makes sense, 0:04:51.920 --> 0:04:55.919 navigating by landmarks. Yeah, and so the maps would reflect that. 0:04:56.520 --> 0:04:58.880 Another thing they point out is that while local maps 0:04:59.480 --> 0:05:03.560 in the ancient world we're one thing, as we're specialized maps, 0:05:03.680 --> 0:05:06.920 broader maps of the world or region, we're not really 0:05:07.040 --> 0:05:09.680 part of the overall ancient approach to maps. There were 0:05:09.720 --> 0:05:12.760 no regular standards of map making, and there were no 0:05:12.880 --> 0:05:17.159 general purpose maps. And uh, this is one quote from 0:05:17.200 --> 0:05:22.200 the book I thought was rather telling quote between them rulers, generals, sailors, 0:05:22.240 --> 0:05:26.359 and traders evidently all but ignored the practical assistance that 0:05:26.480 --> 0:05:30.960 maps could afford them. That's surprising. Yeah, I mean hindsight 0:05:31.080 --> 0:05:34.320 twenty but uh, yeah, it's interesting to look back and 0:05:34.760 --> 0:05:39.400 think about what benefits this broader approach to maps general 0:05:39.400 --> 0:05:43.160 purpose maps, etcetera. Could have afforded them, So I think 0:05:43.160 --> 0:05:45.240 all that's worth keeping in mind as we proceed here. 0:05:45.279 --> 0:05:47.200 None of this is to say peoples during these eras 0:05:47.200 --> 0:05:51.640 were not concerned with precise distances, but the relationship with 0:05:51.720 --> 0:05:54.479 exact maps wasn't quite the same as what we have 0:05:54.600 --> 0:05:57.440 now now. Another way of thinking about what came before 0:05:57.800 --> 0:06:02.840 is that there certainly were ways of measuring long distances 0:06:02.880 --> 0:06:07.040 before the invention of the mechanical odometer. Though there is 0:06:07.080 --> 0:06:10.760 some question about the relative accuracy of early mechanical methods 0:06:10.880 --> 0:06:14.880 versus pre mechanical methods, and one case study here that 0:06:14.920 --> 0:06:17.320 I think we should look at. It's very interesting puzzle 0:06:17.440 --> 0:06:22.440 that emerges if you look at a geography chapter of 0:06:22.520 --> 0:06:25.720 The Natural History by by our old friend Plenty of 0:06:25.720 --> 0:06:28.800 the Elder. Here I'll be referring to the Bostock and 0:06:28.880 --> 0:06:32.400 Riley translation for those not familiar. Plenty of the Elder 0:06:32.600 --> 0:06:36.240 was a first century Roman military commander and author, and 0:06:36.279 --> 0:06:39.640 the Natural History is an early attempt at creating a 0:06:39.680 --> 0:06:44.200 sort of world encyclopedia. So Plenty covers everything from mining 0:06:44.320 --> 0:06:49.719 and metallurgy to botany and zoology, cooking, politics. It's just 0:06:49.880 --> 0:06:53.600 it's just a book of everything, and in book six 0:06:53.839 --> 0:06:57.080 of the Natural History, Plenty sets out to describe, quote, 0:06:57.120 --> 0:07:02.719 an account of countries, nations, sees to ounds, havens, mountains, rivers, distances, 0:07:02.800 --> 0:07:07.520 and peoples who now exist or formerly existed. Very good 0:07:07.600 --> 0:07:11.040 chapter heading there. One of the chapters within this volume, 0:07:11.160 --> 0:07:15.040 chapter twenty one, is on the nations of India, as 0:07:15.160 --> 0:07:17.600 known to Plenty at the time. Again, this is the 0:07:17.640 --> 0:07:21.560 first century CE. So Plenty says that India is a 0:07:21.640 --> 0:07:25.200 vast country with over a hundred kingdoms, dozens of rivers, 0:07:25.320 --> 0:07:29.240 uncountable mountains, but he will undertake to describe some of 0:07:29.280 --> 0:07:33.200 it by following the path of Alexander the Great, who 0:07:33.360 --> 0:07:37.480 led a conquering army to India about four hundred years earlier. 0:07:38.720 --> 0:07:42.280 So Plenty rights quote, however, that we may come to 0:07:42.320 --> 0:07:45.600 a better understanding relative to the description of these regions. 0:07:45.640 --> 0:07:49.800 We will follow the track of Alexander the Great. Diagonitis 0:07:50.000 --> 0:07:53.960 and Biton, whose duty it was to ascertain the distances 0:07:54.000 --> 0:07:57.160 and length of his expeditions, have written that from the 0:07:57.200 --> 0:08:01.800 Caspian Gates to hecatom Pylon, the city of the Ptarthians, 0:08:01.840 --> 0:08:04.400 the distance is the number of miles, which we have 0:08:04.480 --> 0:08:07.320 already stated and he mentioned a number earlier, and then 0:08:07.320 --> 0:08:10.760 he goes on and that from thence to Alexandria of 0:08:10.800 --> 0:08:13.760 the ri I, which city was founded by the same king, 0:08:13.840 --> 0:08:17.200 the distance is five hundred and seventy five miles, and 0:08:17.320 --> 0:08:21.160 from thence to Prophesia, the city of the drag Ni, 0:08:21.440 --> 0:08:24.760 one hundred and ninety nine miles. And from here he 0:08:24.880 --> 0:08:28.520 just goes on and on, listing distances. It's this many 0:08:28.520 --> 0:08:30.520 miles to the next city, and this many miles to 0:08:30.560 --> 0:08:35.040 the next city. Uh. So he attributes all of these numbers, 0:08:35.080 --> 0:08:37.720 all of these distances and miles that he comes up 0:08:37.760 --> 0:08:41.800 with for this path leading into India to these two figures, 0:08:41.920 --> 0:08:46.560 Diagnetis and Biton. Who were these guys well, they were 0:08:46.600 --> 0:08:52.040 known as Bimatists, coming from the Greek word meaning step 0:08:52.360 --> 0:08:56.600 or pace. I looked up Bimatists in the Oxford Handbook 0:08:56.640 --> 0:09:00.079 of Classics, and the entry does identify them as the 0:09:00.080 --> 0:09:04.400 the surveyors essentially of Alexander the Great Uh and names 0:09:04.440 --> 0:09:06.840 a few other ones. In addition to the two already 0:09:06.840 --> 0:09:11.520 mentioned Byton and Diagnetus. It also names uh Philonides of Crete, 0:09:11.840 --> 0:09:14.360 who it says in a side note, was a celebrated 0:09:14.440 --> 0:09:18.640 distance runner, and the entry also notes that the two 0:09:18.679 --> 0:09:22.559 figures who worked for Alexander, Byton and Diagnetus, as well 0:09:22.600 --> 0:09:26.959 as some others quote had literary aspirations. Their measurements of 0:09:27.080 --> 0:09:31.480 key distances in the empire comprised an archive later controlled 0:09:31.480 --> 0:09:36.320 by Seleucus. The first individual Bemetists published their observations in 0:09:36.400 --> 0:09:42.480 monographs termed stath moy or Stages, which combined precise calculations 0:09:42.480 --> 0:09:46.040 of distance with more exotic reports of the flora, fauna, 0:09:46.120 --> 0:09:50.160 and customs of the empire. The latter tended to the outrageous, 0:09:50.160 --> 0:09:53.640 but the measurements were of lasting value and provided Eratas 0:09:53.720 --> 0:09:57.440 the Knees with the framework for his geography of Asia. 0:09:57.520 --> 0:10:00.600 Aretas the Nees, you might recall, was an really figure, 0:10:00.679 --> 0:10:07.000 a Greek philosopher who with pretty startling accuracy, calculated the 0:10:07.080 --> 0:10:11.000 actual size of the sphere of the Earth. And he 0:10:11.040 --> 0:10:15.920 did that just using knowledge of the distances between locations 0:10:16.000 --> 0:10:20.680 of different latitudes and then the use of the angles 0:10:20.800 --> 0:10:25.560 of sundials. Basically, yeah, So, how did the Bematists actually 0:10:25.600 --> 0:10:28.800 measure distances in the time of Alexander the Great? Well, 0:10:29.720 --> 0:10:33.280 I've seen some disagreement on this, some sources imply that 0:10:33.360 --> 0:10:37.240 they simply counted paces, so you'd walk and count how 0:10:37.240 --> 0:10:40.600 many steps you took, while others suggest that they used 0:10:40.679 --> 0:10:44.720 some kind of mechanical device. One of the weird things 0:10:44.800 --> 0:10:46.840 is that, as far as we can tell, most of 0:10:46.880 --> 0:10:50.920 the distances recorded by bematists such as Biton and Diagnetis, 0:10:51.520 --> 0:10:55.040 as well as others from the ancient world, are surprisingly accurate. 0:10:56.000 --> 0:10:57.760 On this point, I want to quote a book I 0:10:57.800 --> 0:11:02.520 was looking at by a American historian named Donald W. Ingalls. 0:11:02.920 --> 0:11:05.640 The book is called Alexander the Great and the Logistics 0:11:05.640 --> 0:11:09.280 of the Macedonian Army from the University of California Press 0:11:09.360 --> 0:11:13.240 in nineteen seventy eight. And explaining a table in his 0:11:13.320 --> 0:11:17.880 book of the bimatists different estimates of the distances between 0:11:17.920 --> 0:11:21.920 cities on this route, ingles rights quote the overall accuracy 0:11:21.920 --> 0:11:25.960 of the bimatists measurements should be apparent. The minor discrepancies 0:11:26.000 --> 0:11:30.320 of distance parentheses only one point three percent from herat 0:11:30.320 --> 0:11:34.040 to begrum, can be adequately explained by slight changes in 0:11:34.080 --> 0:11:37.640 the tracks of roads during the last twenty three hundred years. 0:11:38.160 --> 0:11:41.800 The accuracy of the measurements implies that the bimatists used 0:11:41.800 --> 0:11:47.520 a sophisticated mechanical device for measuring distances, undoubtedly an odometer, 0:11:48.080 --> 0:11:52.439 such as described by Heron of Alexandria. So there's a clue. 0:11:52.840 --> 0:11:57.000 Uh Ingles here says, Look, the distance is given by 0:11:57.000 --> 0:11:59.640 these these people who worked for Alexander the Great and 0:11:59.720 --> 0:12:03.160 other immotists of the era. They're just too accurate. They're 0:12:03.200 --> 0:12:05.520 too good to be the result of trying to count 0:12:05.600 --> 0:12:08.800 your steps and estimate from that. They have to be 0:12:08.920 --> 0:12:11.760 using some kind of machine that we don't know about, 0:12:12.120 --> 0:12:14.720 and one good candidate is a machine like the one 0:12:14.760 --> 0:12:19.480 described later by Heron of Alexandria. Now, this idea that 0:12:19.520 --> 0:12:22.720 they may have simply been walking, on one hand, I 0:12:22.720 --> 0:12:25.160 can't help but think of the Monty Python ministry of 0:12:25.240 --> 0:12:29.160 silly walks and imagine like a specific, ridiculous but regular 0:12:29.240 --> 0:12:32.720 date that they're using, and and if they were super 0:12:32.720 --> 0:12:36.200 focused on their steps and counting their steps, maybe that 0:12:36.200 --> 0:12:40.199 would explain why they're reports of flora and fauna are 0:12:40.200 --> 0:12:43.040 so outrageous. They're like, well, I was it was. It 0:12:43.160 --> 0:12:47.000 was three thousand, eight hundred and seventies six steps. And 0:12:47.080 --> 0:12:49.120 to the left there may have been a dragon. I'm 0:12:49.160 --> 0:12:51.400 not sure. I was just really focused on these steps 0:12:51.440 --> 0:12:54.160 and getting the step count right. I mean, descriptions of 0:12:54.200 --> 0:12:59.319 local flora, fauna, and people's of the world are notably 0:12:59.400 --> 0:13:03.360 hilarious throughout all kinds of ancient texts, including Plenty himself. 0:13:04.240 --> 0:13:06.360 He loves to talk about people who had like eyes 0:13:06.440 --> 0:13:09.840 in their stomachs and stuff. Yeah. I keep hoping one 0:13:09.920 --> 0:13:11.920 day I'll come across a passage in Plenty where he 0:13:12.160 --> 0:13:16.920 mentions people who have crab clause. I haven't found that yet. Oh, 0:13:16.960 --> 0:13:18.360 I have to have to look into that, I mean, 0:13:18.400 --> 0:13:20.880 because you mentioned it's it's of course not just Plenty 0:13:20.960 --> 0:13:23.720 in his writings and travelers that he's sourcing, and we 0:13:23.720 --> 0:13:26.880 we've discussed similar things in Chinese traditions as well, So 0:13:26.920 --> 0:13:30.240 there have to be some crab claude individuals out there somewhere. 0:13:30.400 --> 0:13:34.560 But okay, sorry to Hero or Heron of Alexandria. Multiple 0:13:34.600 --> 0:13:38.280 sources I found point to a device described by this 0:13:38.440 --> 0:13:43.040 first century mathematician and inventor, sometimes known as Hero, sometimes 0:13:43.040 --> 0:13:46.559 known as Iron, but he was from Alexandria, Alexandria, Egypt. 0:13:46.559 --> 0:13:48.920 As you can tell by the name. A lot of 0:13:48.960 --> 0:13:51.959 inventions are attributed to Hero, though some of the most 0:13:52.040 --> 0:13:56.880 famous ones probably predated him, and he just described them 0:13:56.920 --> 0:13:59.480 in lectures and writings, and then later that gets sort 0:13:59.520 --> 0:14:02.960 of mistaken for him having actually invented the thing in 0:14:02.960 --> 0:14:06.520 the first place. In the latter category. One example, in fact, 0:14:06.520 --> 0:14:10.360 one of the most famous devices associated with Hero is 0:14:10.400 --> 0:14:13.360 the Yala pile, which is a type of early steam 0:14:13.400 --> 0:14:18.520 engine converting the power of steam into rotational energy. Basically 0:14:18.559 --> 0:14:20.960 it works, but you've got a big cauldron this full 0:14:21.000 --> 0:14:23.240 of water, and then you put a fire underneath it, 0:14:23.560 --> 0:14:27.120 and then that cauldron is connected by pipes to a 0:14:27.280 --> 0:14:31.160 sphere that can rotate around the pipes, and then the 0:14:31.240 --> 0:14:36.880 sphere has two little exhaust nozzles that allow steam to 0:14:37.040 --> 0:14:40.880 escape as the water boils and turns into steam and expands. 0:14:40.880 --> 0:14:44.440 But the way the nozzles are oriented, they're oriented in 0:14:44.520 --> 0:14:47.880 the same rotational direction, so as the as it gets 0:14:47.920 --> 0:14:50.400 hotter and hotter and the cauldron and the steam pressure 0:14:50.440 --> 0:14:54.240 builds up, it spins the sphere faster and faster. Yeah, 0:14:54.280 --> 0:14:56.840 there are a lot of images of this, as I recall, 0:14:56.920 --> 0:14:59.360 I remember seeing a cool woodcut of this, I think 0:14:59.440 --> 0:15:03.000 at one point um but it has a look of 0:15:02.800 --> 0:15:06.920 of a novelty of a device that's that's illustrating the 0:15:06.920 --> 0:15:09.520 principle here, but but of course not putting it to 0:15:09.920 --> 0:15:13.280 the sort of work that later UH steam engines would. 0:15:13.360 --> 0:15:16.240 For sure. Yes, and though the e Allo pile is 0:15:16.400 --> 0:15:20.440 often associated with UH, with Hero, I think this is 0:15:20.480 --> 0:15:23.880 something that he very likely did not actually invent. It 0:15:23.920 --> 0:15:27.600 was just something he described that already existed. UM. But 0:15:27.680 --> 0:15:31.600 we have talked about other machines possibly invented by Hero 0:15:31.720 --> 0:15:34.680 in previous episodes. One that I remember is the Hero 0:15:34.760 --> 0:15:39.000 of alexandrias In is credited with inventing the first vending machine, 0:15:39.320 --> 0:15:43.160 which strangely was also a piece of religious technology. It 0:15:43.240 --> 0:15:47.640 was a machine designed to dole out limited portions of 0:15:47.760 --> 0:15:52.560 sacred water within Egyptian temples when a devotee would insert 0:15:52.720 --> 0:15:54.920 the right amount of coinage. So I think you'd put 0:15:54.920 --> 0:15:58.160 a five drachma or five drama piece in through a 0:15:58.200 --> 0:16:01.520 coin slot, and then that would operate a weighted lever 0:16:01.800 --> 0:16:04.760 that would dispense a certain amount of holy water, and 0:16:04.800 --> 0:16:06.840 then once a certain amount of water had gone out, 0:16:06.920 --> 0:16:09.240 the machine would tip over and then it would close 0:16:09.280 --> 0:16:12.440 the valve and stop dispensing. Though even in this case, 0:16:12.480 --> 0:16:16.160 I read that it's actually possible Hero was simply describing 0:16:16.160 --> 0:16:18.760 a device that had already been invented by two Cbs 0:16:18.840 --> 0:16:22.280 of Alexandria in the third century BC. So, as with 0:16:22.320 --> 0:16:24.560 a lot of ancient inventions, it's often hard to tell 0:16:25.120 --> 0:16:28.240 if somebody actually invented something or if they're just talking 0:16:28.280 --> 0:16:32.880 about something that already existed. Anyway, I found multiple references 0:16:32.920 --> 0:16:37.680 to Hero either inventing or describing an odometer, as evidenced 0:16:37.680 --> 0:16:40.600 by a passage he wrote in a minor work called 0:16:40.680 --> 0:16:44.200 the Dioptera, which I wanted to find the full text for, 0:16:44.760 --> 0:16:47.400 but if it has been translated into English, I was 0:16:47.480 --> 0:16:50.040 unable to find it, so I don't know if that 0:16:50.080 --> 0:16:53.440 even exists in English. But regarding this, this machine he 0:16:53.520 --> 0:16:56.880 describes in the diopter again, the Hero is first century CE. 0:16:57.720 --> 0:17:00.520 A couple of caveats. One is that he Hero was 0:17:00.600 --> 0:17:04.280 definitely not the first known author to describe an odometer 0:17:04.440 --> 0:17:07.480 in Greek. In the Greek and Latin Corpus, the Roman 0:17:07.520 --> 0:17:11.439 engineer Vitruvius, who lived in the first century BC, so 0:17:12.000 --> 0:17:16.879 century before Hero, also describes an odometer, uh, though in 0:17:16.880 --> 0:17:19.080 a slightly different way. I'll get into the differences in 0:17:19.119 --> 0:17:22.199 a minute. But even Vitruvius does not claim to have 0:17:22.320 --> 0:17:25.200 invented the device out of whole cloth. And then there's 0:17:25.200 --> 0:17:29.359 a second caveat which is that remember again Ingles making 0:17:29.400 --> 0:17:32.159 the comment that Alexander the Great's bimatists must have had 0:17:32.240 --> 0:17:36.040 a device like Heroes. The problem here is that hero 0:17:36.119 --> 0:17:40.679 of Alexandria and Vitruvius both lived along after the conquest 0:17:40.680 --> 0:17:43.960 of Alexander the Great. So if it's true as Ingles 0:17:44.000 --> 0:17:48.439 suggests that these bimatists used a mechanical odometer similar to 0:17:48.440 --> 0:17:52.640 the one described by these engineers and authors, they would 0:17:52.680 --> 0:17:56.080 have been using some kind of earlier device similar to 0:17:56.280 --> 0:17:59.880 Heroes or Vitruvious. Is not something that hero or Vitruvious 0:17:59.880 --> 0:18:03.280 and vented. Now. An interesting source I found on on 0:18:03.760 --> 0:18:08.879 these two device descriptions is a book called Technical Exprassis 0:18:09.160 --> 0:18:13.080 in Greek and Roman Science and Literature, The Written Machine 0:18:13.160 --> 0:18:16.560 between Alexandria and Rome. This is by an author named 0:18:16.640 --> 0:18:21.720 Courtney Roby from Cambridge University Press. Courtney Roby is a 0:18:21.800 --> 0:18:25.840 professor of classics at Cornell and in this book, this 0:18:25.920 --> 0:18:29.639 is in the context of explaining patterns of composition in 0:18:29.720 --> 0:18:33.600 Greek and Roman technical books, how in different times and 0:18:33.640 --> 0:18:37.960 cultures there were different standards and uses for technical explanation 0:18:38.000 --> 0:18:43.720 of machinery. Hero and Vitruvius both wrote books describing odometers. 0:18:43.720 --> 0:18:47.200 I mentioned Heroes, but the the earlier mentioned by Vitruvius 0:18:47.200 --> 0:18:51.679 comes in a book called on Architecture, and according to Roby, 0:18:52.280 --> 0:18:56.679 Vitruvius himself acknowledges that the odometer is quote part of 0:18:56.680 --> 0:19:02.399 a technological tradition handed down from predecessors. Some authors have 0:19:02.600 --> 0:19:06.080 suggested that might mean from Archimedes, but I'm not aware 0:19:06.080 --> 0:19:08.520 of what what evidence there would be for this, so 0:19:09.000 --> 0:19:11.560 I'm not sure how strong that suggestion is. Maybe it's 0:19:11.560 --> 0:19:13.840 just kind of like, oh, Archimedes, he invented stuff, and 0:19:13.880 --> 0:19:16.120 maybe it's him. Yeah, I think some sometimes we see 0:19:16.119 --> 0:19:21.600 in different traditions we have these these noted inventors, noted minds, 0:19:21.640 --> 0:19:26.520 and they kind of become mythic magnets for various ideas 0:19:26.520 --> 0:19:29.240 and inventions. But there might be some good reasons for 0:19:29.240 --> 0:19:31.359 think of our comedies. I just don't know if there is. 0:19:31.400 --> 0:19:39.760 I did not turn it up than the basic principle, 0:19:39.800 --> 0:19:42.480 how does this odometer work? So you've got a chariot wheel. 0:19:42.680 --> 0:19:45.679 Odometer typically has a wheel of some kind that is 0:19:45.800 --> 0:19:48.359 rolling on the ground and that's your your basic point 0:19:48.359 --> 0:19:51.840 of contact with the Earth to get the the baseline 0:19:51.840 --> 0:19:54.439 measurement of distance. So you've got a chariot wheel of 0:19:54.480 --> 0:19:59.040 a fixed size two Roman feet in radius, which Vitruvius 0:19:59.040 --> 0:20:03.439 says h gives the wheel a circumference of approximately twelve 0:20:03.560 --> 0:20:07.480 point five Roman feet. So if the radius is two, 0:20:07.560 --> 0:20:11.800 that's four times pie, which is about twelve point five six. 0:20:12.080 --> 0:20:15.240 So when Vitrivius has twelve point five Roman feet, he's 0:20:15.240 --> 0:20:19.000 sort of approximating in his explanation. But anyway, each time 0:20:19.000 --> 0:20:22.440 the chariot wheel makes a full revolution, it will advance 0:20:22.480 --> 0:20:25.200 a cog wheel by one cog position, you know, one 0:20:25.280 --> 0:20:28.959 tooth advances and the cog has the cog wheel has 0:20:29.000 --> 0:20:31.880 a fixed number of teeth, meaning that it will make 0:20:31.920 --> 0:20:36.280 a full revolution once the wheel has traveled one Roman mile. 0:20:37.160 --> 0:20:40.199 Every time this cog wheel makes a full revolution, it 0:20:40.240 --> 0:20:43.879 will advance a gear that pushes a single small object 0:20:43.960 --> 0:20:47.320 like a pebble or a bead into a receptacle. And 0:20:47.320 --> 0:20:49.679 then at the end of the journey, you simply have 0:20:49.760 --> 0:20:52.280 a human count up the beans, you know, count up 0:20:52.320 --> 0:20:55.560 whatever the little pebbles or beads or beans are to 0:20:55.720 --> 0:20:58.280 know how many miles you've gone. And I want to 0:20:58.280 --> 0:21:01.000 make a note that this seemed interesting to me, that 0:21:01.520 --> 0:21:04.800 this is the principle of using a system of gears 0:21:04.920 --> 0:21:08.640 as a type of analog computer, similar to the use 0:21:08.680 --> 0:21:12.480 of gears in the ancient astronomical computer known as the 0:21:12.520 --> 0:21:16.080 Antikithera mechanism. We discussed this in an episode we did 0:21:16.200 --> 0:21:18.000 sometime in the past couple of years. It might have 0:21:18.040 --> 0:21:21.480 been in the Creature of the Gear episode about biological gears. 0:21:22.320 --> 0:21:25.600 But the idea that we often think of a gear 0:21:25.760 --> 0:21:29.600 is something that creates mechanical advantage, and it certainly does 0:21:29.640 --> 0:21:34.920 do that, but a gear can also manage ratios between numbers, 0:21:34.960 --> 0:21:38.000 like a gear can do math for you, and that's 0:21:38.040 --> 0:21:40.960 what it's doing in the case of this odometer. Yeah, 0:21:41.000 --> 0:21:44.840 I love these these examples of them from the ancient 0:21:44.880 --> 0:21:47.800 birth of the odometer or possible birth of the odometer, 0:21:47.880 --> 0:21:50.600 and some of these these instances, because it seems it's's 0:21:50.640 --> 0:21:53.080 kind of like we have the wheel turning on the road, 0:21:53.480 --> 0:21:55.760 and then it's a question of could we put that 0:21:55.760 --> 0:21:58.359 wheel to use, Like the wheel is already in a 0:21:58.440 --> 0:22:02.720 sense marking the distance in its revolution, and and in 0:22:02.720 --> 0:22:05.720 that it's kind of like the heavens. It's like the sun. 0:22:05.800 --> 0:22:09.120 It's like the moon, it's like the the cyclical movements 0:22:09.119 --> 0:22:11.720 all around us that mark the passage of time. Yeah, 0:22:11.800 --> 0:22:14.520 you just need to correlate something with like a fixed 0:22:14.560 --> 0:22:17.600 number of teeth that you can count to those pre 0:22:17.680 --> 0:22:21.600 existing revolutions, and then you take those teeth to do 0:22:21.680 --> 0:22:24.040 some kind of work that will help you keep the count, 0:22:24.119 --> 0:22:26.719 like dropping a bean in a bucket, or advancing a 0:22:26.760 --> 0:22:29.000 dial to on a fixed face that has a number 0:22:29.000 --> 0:22:31.280 printed on it. Yeah, and it and it. You can 0:22:31.320 --> 0:22:34.159 imagine that into the in the ancent minds like you 0:22:34.320 --> 0:22:36.600 would have realized if we could harness this, like this 0:22:36.680 --> 0:22:40.320 is better than than than counting your steps. There's a 0:22:40.359 --> 0:22:44.720 regularity to this that would be harder to achieve through 0:22:44.720 --> 0:22:48.760 other means. Totally so so. Vitruvius describes a machine roughly 0:22:48.840 --> 0:22:53.120 like that. Hero later describes a similar machine, but there 0:22:53.119 --> 0:22:56.120 are some interesting differences in how the two authors present 0:22:56.320 --> 0:23:02.199 their explication. For example, Vitruvius describes his dodometer with fixed dimensions. 0:23:02.240 --> 0:23:05.840 The wheel is four Roman feet in diameter, the circumference 0:23:05.920 --> 0:23:09.199 is approximately twelve point five feet, and so forth. And 0:23:09.240 --> 0:23:11.680 here I want to read a passage from Roby quote. 0:23:12.240 --> 0:23:16.240 Rather than providing a mathematical formula whereby the odometer could 0:23:16.240 --> 0:23:19.920 be adapted to any desirable or available wheel size, as 0:23:20.000 --> 0:23:23.640 Hero does for his own description of an odometer, Vitruvious 0:23:23.680 --> 0:23:28.200 avoids formulas and geometrical language by specifying the wheel diameter 0:23:28.320 --> 0:23:31.840 and circumference as fixed numbers. That is to say, the 0:23:31.960 --> 0:23:34.879 version of the odometer he gives his reader is presented 0:23:34.960 --> 0:23:40.399 as the exact device transmitted from his quote predecessors, not 0:23:40.680 --> 0:23:44.680