10-12-2006, 03:14 AM
I added a small passage at Wikipedia's entry "Odometer" which argues for an early use of the odometer by the Bematists which accompanied Alexander's campaign. My passage is based exclusively on Donald W. Engels: Alexander the Great and the Logistics of the Macedonian Army, Los Angeles 1978, p.157f.
Personally, I am convinced that the Bematists must have used some kind of odometer, but I just talked with a friend of mine who remained sceptical. The question is whether the surviving measurements given by Pliny and Strabo are so accurate that pacing them off would have been an impossibility and thus an odometer the only viable explanation.
My friend argued that perhaps much more bematists were pacing the routes than the two below, but I fail to see the advantage of having 10, 50 or a 100 bematists over just two: The better measures by some of them will just be offset by worse measures of other, leveling things ultimately out, as in the absence of other methods nobody can know which are the better or the worse ones.
Looking at the most accurate measures with less than 1% deviation from the actual distance, I further fail to see how a human being can measure his steps in such a precise way. Assumed that the bematists made measured strides of 1 meter, a 1% deviation means an average deviation per step of a fifth of the length of the big toe (which is in my case 5 cm)! Even the second largest recorded deviation of 5% would still mean an average deviation of only the length of the big toe! How can a human being hope to measure his steps in such a precise way? Continously on marches of up to 530 English miles? Which took up to 35 days (Engels give an average march speed of 15mpd, rest days not counted)?
I seriously doubt it, but I would like to hear your opinion? Did Alexander's Bematists use an odometer or not?
Personally, I am convinced that the Bematists must have used some kind of odometer, but I just talked with a friend of mine who remained sceptical. The question is whether the surviving measurements given by Pliny and Strabo are so accurate that pacing them off would have been an impossibility and thus an odometer the only viable explanation.
My friend argued that perhaps much more bematists were pacing the routes than the two below, but I fail to see the advantage of having 10, 50 or a 100 bematists over just two: The better measures by some of them will just be offset by worse measures of other, leveling things ultimately out, as in the absence of other methods nobody can know which are the better or the worse ones.
Looking at the most accurate measures with less than 1% deviation from the actual distance, I further fail to see how a human being can measure his steps in such a precise way. Assumed that the bematists made measured strides of 1 meter, a 1% deviation means an average deviation per step of a fifth of the length of the big toe (which is in my case 5 cm)! Even the second largest recorded deviation of 5% would still mean an average deviation of only the length of the big toe! How can a human being hope to measure his steps in such a precise way? Continously on marches of up to 530 English miles? Which took up to 35 days (Engels give an average march speed of 15mpd, rest days not counted)?
I seriously doubt it, but I would like to hear your opinion? Did Alexander's Bematists use an odometer or not?
Quote:Perhaps the first evidence for the use of a odometer can be found in the works of the Roman authors Pliny (NH 6. 61-62) and Strabo (11.8.9). Both authors list the distances of routes traveled by Alexander the Great (r. 336-323 BC) as measured by his bematists Diognetus and Baeton. Bematists were specialists who accompanied Alexander's army and measured the distances by counting their steps. However, the high precision of the bematists's measurements rather indicates the use of a mechanical device. For example, the section between the cities Hecatompylos and Alexandria Areion, which later became a part of the silk road, was given by Alexander's bematists as 529 English miles long, that is with a deviation of 0.4% from the actual distance (531 English miles). From the nine surviving bematists' measurements in Pliny's Naturalis Historia eight show a deviation of less than 5% from the actual distance. Three of them even less than 1%. Since these minor discrepancies can be adequately explained by slight changes in the tracks of roads during the last 2300 years, the overall accuracy of the measurements implies that the bematists must have already used a sophisticated mechanical device for measuring distances, although there is no direct mentioning of a odometer.
http://en.wikipedia.org/wiki/Odometer
Stefan (Literary references to the discussed topics are always appreciated.)
