*O COSMOS. 



outer crust, the figure of the surface cannot be assumed to 

 be locally modified by the internal motion of the fused 

 masses. The difference of the results of pendulum measure- 

 ments is however much too great to be ascribed at the pre- 

 sent day to errors of observation. Even where a coinci- 

 dence in the results, or an obvious regularity has been dis- 

 covered by the various grouping and combination of the 

 points of observation, the pendulum always gives a greater 

 ellipticity (varying between the limits -^y and -3 ~o) than 

 could have been deduced from the measurements of a degree. 

 If we take the ellipticity which, in accordance with 

 Bessel's last determination, is now generally adopted, 

 namely, ^^Jy^, we shall find that the bulging 23 at the 



23 In Grecian antiquity two regions of the earth were designated as 

 being characterised, in accordance with the prevalent opinions of the 

 time, by remarkable protuberances of the surface, namely, the high 

 north of Asia and the land lying under the equator. " The high and 

 naked Scythian plains," says Hippocrates (de Acre et Aquis xix, p. 72, 

 Littre"), "without being crowned by mountains stretch far upward to 

 the meridian of the Bear." A similar opinion had previously been 

 ascribed to Empedocles (Plut. de Plac. Philos. ii, 8). Aristotle (Meteor. 

 i, 1 a 1 5, p. 66, Ideler) says that the older meteorologists, according to 

 whose opinions the sun " did not go under the earth, but passed round 

 it," considered that the protuberances of the earth towards the north 

 were the cause of the disappearance of the sun, or of the production of 

 night. And in the compilation of the Problems (xxvi, 15, page 941, 

 Bekker), the cold of the north wind was ascribed to the elevation of 

 the soil in this region of the earth, and in all these passages there is 

 no reference to mountains, but merely to a bulging of the earth into 

 elevated plateaux. I have already elsewhere shown (Asie Centrale, t. i, 

 p. 58) that Strabo, who alone makes use of the very characteristic word 

 opoTridia, says that the difference of climate which arises from geogra- 

 phical position must everywhere be distinguished from that which we 

 ascribe to elevation above the sea, in Armenia (xi, p. 522, Casaub.), in 

 Lycaonia, which is inhabited by wild assea (xii, p. 568), and in Upper 

 India, in the auriferous country of the Derdi (xv, p. 706). " Even in 

 southern parts of the world," says the geographer of Amasia, " every 

 high district, if it be also a plain, is cold " (ii, p. 73). Eratosthenes 

 and Polybius ascribe the very moderate temperature which prevails 

 under the equator not only to the more rapid transit of the sun 

 (Geminus, JElem. Astron. c. 13, Cleom. Cycl. Theor., 1, 6), but more espe- 

 cially to the bulging of the earth (See my Examen Grit, de la Geogr. 

 t. iii, pp. 150 152). Both maintain, according to the testimony of 

 Strabo (ii, p. 97), " that the district lying immediately below the equator 

 is the highest, on which account much rain falls there, in consequence 

 of the very large accumulation of northern clouds at the period when 



