Bematist
Bematists (Greek βηματιστής, 'striding; step counter') were specialists in ancient Greece who were trained to measure distances by counting their steps.
Measurements by Alexander's Bematists
Bematists accompanied Alexander the great on his campaign through Asia . Their distance information is so precise that it has been suggested that they must have used an odometer , although there is no direct mention of such a device:
“The accuracy of the bematists' distance measurements should be evident. The smaller deviations can be explained by minor changes in the course of the road over the past 2300 years. The precision of the information implies that the Bematists used a sophisticated mechanical device to measure distances - undoubtedly an oodometer as described by Heron of Alexandria . "
The following table lists the distances as measured by two of Alexander's Bematists (Diognetus and Baeton). The measurements were recorded in the Naturalis Historia by Pliny ( NH 6.61-62). Further information is given in Strabo (Geographica 11.8.9), followed by Eratosthenes .
Pliny 6.61-62 | Strabo 11.8.9 | Real distance | |||||
---|---|---|---|---|---|---|---|
route | Milia passuum 1) | English miles | deviation | Stages 2) | English miles | deviation | English miles |
North. Caspian Gate - Hekatompylos | - | - | - | 1960 | 225 | 0.8% | 227 main street |
South. Caspian Gate - Hekatompylos | 133 | 122 | 2.4% | - | - | - | 125 main street |
Hekatompylos - Alexandria Areion | 575 | 529 | 0.4% | 4530 | 521 | 1.9% | 531 Silk Road |
Alexandria Areion - Prophtasia | 199 | 183 | 3.2% | 1600 | 184 | 2.6% | 189 Herat - Juwain |
Prophtasia - Arachoti Polis | 565 | 520 | 1 % | 4120 | 474 | 9.7% | 525 Juwain - Kelat-i-Ghilzai |
Arachoti Polis - Hortospana | 250 | 230 | 0.4% | 2000 | 230 | 0.4% | 231 Main street Kelat-i-Ghilzai - Kabul |
Hortospana - Alexandria ad Caucasum | 50 | 46 | 2.1% | - | - | - | 47 Kabul - shame |
Alexandria ad Caucasum - Peucolatis | 237 | 218 | 3.2% | - | - | - | 211 Begram - Charsada |
Peucolatis - Taxila | 60 | 55 | 20% | - | - | - | 69 Charsada - Taxila |
Taxila - Hydaspes (Jhelum) | 120 | 110 | 4.8% | - | - | - | 105 Aurel Stein's route |
Alexandria Areion - Baktra - Zariaspa 3) | - | - | - | 3870 | 445 | 1.6% | 438 via Kala Nau, Bala Murghab, Maimana and Andkhui |
average | 4.2% | 2.8% | |||||
Median | 2.8% | 1.9% |
Appendix: If the highest statistical outlier is disregarded, the average deviation of the remaining measurements of the Bematists from the real distance is 1.9% for Pliny and 1.5% for Strabo, with a total distance of 1958 and 1605 miles, respectively.
Individual evidence
literature
- Engels, Donald W .: Alexander the Great and the Logistics of the Macedonian Army , University of California Press, Los Angeles 1978, ISBN 0-520-04272-7