EARLIEST MEASURES OF THE EARTH 77 



by Aristotle was 400,000 stadia j] 1 Archimedes speaks of 300,000 ; 2 

 Eratosthenes' figure was 250,000 3 (or 252,000) ; Hipparchus 

 wished to increase this to 275,000 ; 4 Poseidonius to reduce it, 

 fixing it at 240,000 5 stadia according to Cleomedes, at 180,000 6 

 according to Strabo. This last figure was that adopted by 

 Ptolemy, 7 and this and other errors of Ptolemy were the basis 

 of Columbus's belief that India was near. Had he known the 

 true distance, possibly he never would have sailed. 



How near was the truth ? We cannot answer, for the 

 exact value of a stadium we do not know. The ill-fated Bailly, 8 

 and following him (without a suggestion of credit) Laplace, 9 

 noting that the varying estimates stand in a simple relation to 

 each other, supposed that they might each be the transposition 

 of an original measure of great antiquity and great accuracy 

 into stadia of varying length. This may be true, but there is 

 a remark of Strabo, 10 near contemporary of Poseidonius, some- 

 what troublesome to this view, wherein he observes : "If, of 

 recent measurements, we prefer those which diminished the size 

 of the globe, such as that adopted by Poseidonius ; which is 

 about 180,000 stadia," &c. as against the 252,000 of Eratos- 

 thenes. 



If the measures were really different, we may conclude that 

 the % closest was the latter, and that it was but little out of the 

 way. It does not appear that any new measures were made 

 in Christendom before those that were made by the French 

 physician, Dr. Fernel, in 1517, five years after the ships of 

 Magalhaens had returned from their circumnavigation of the 

 earth. 



Seven hundred years before, in the golden age of Arabian 

 culture, when all Europe had relapsed into barbarism and 

 Bagdad shone as a centre of learning and of light, a series of 

 measures had been effected on the plains of Shinar and of 



1 De Ccello, ii. 14. 



2 Arenarius, ii., Introduction. 



3 Pliny, ii. 108. 



* Cleomedes, p. 65 ; ed. Blake. 

 5 Cleomedes, loc. cit. 



Strabo, vol. i. p. 140 ; ed. Bohn. 



7 In his " Great Syntaxis " (Almagest of the Arabians). 



8 Histoire de I'Astron. Moderns, tome i. 



9 Exposition du Systtme du Monde, Book V. chap. ii. 



10 Loc. cit., i. p. 114 ; ed. Bohn. 



