Cxlvi NOTES. 



single west and east chain. Strabo says : " The Hellenes term the half of Asia 

 which slopes to the north the Hither Side of the Taurus, and that towards the 

 south the Beyond Taurus " (lib. ii. p. 129). But in the later times of Ptolemy, 

 when commerce, and especially the trade in silk, had become active, the name 

 Imaus was transferred to a meridian chain, that of Bolor, as is shown by many 

 passages in the sixth book. (Asie Centr. t. i. p. 146 162.) The line in 

 which, according to Hellenic views, the Taurus mountains parallel to the equator 

 were supposed to divide the whole continent, was first termed, by Dicasarchus a 

 ' disciple of the Stagirite, " a diaphragm," or dividing-wall, because the geogra- 

 phical latitude of other points could be measured by perpendicular lines drawn 

 to it. The Diaphragm was the parallel of Rhodes prolonged, to the westward 

 to the Pillars of Hercules, and to the eastward to the coast of Thinaa. (Aga- 

 themeros, in Hudson's Geogr. Gr. Min. vol. ii. p. 4.) The Diaphragm, or 

 " Divider," of Dicasarchus, alike interesting in geographical and in orographical 

 respects, passed into the work of Eratosthenes, where he refers to it in the third 

 book of descriptive geography, in explaining his table of the inhabited world. 

 Strabo attaches so much importance to this line that (in lib. i. p. 65) he says : 

 " Its eastern prolongation beyond Thinaa through the Atlantic Sea may possibly 

 be the site of another inhabited world, or even of several worlds," though he does 

 not, strictly speaking, predict the existence of such. It may excite surprise that 

 he should use the word " Atlantic " instead of Eastern Sea, the name usually 

 given to the Pacific Ocean ; but as our Indian Sea south of Bengal is called in 

 Strabo " the Atlantic South Sea," the two seas, which were assumed to unite on 

 the south-east of India, were often confounded. Thus, in lib. ii. p. 130, it is 

 said, " India, the greatest and most favoured of lands, which terminates at the 

 Eastern Sea and at the Atlantic South Sea;" and in lib. xv. p. 689, " The 

 southern and eastern sides of India, which are much greater than the other 

 sides, run into the Atlantic Sea;" in which last passage, as well as in that 

 before referred to relative to Thina3 (lib. i. p. 65), the expression of Eastern Sea 

 seems even to be avoided. Having been constantly occupied, since the year 

 1792, with the " strike " and " dip" of mountain-strata, and with their relations 

 to the geographical direction of the mountain-chains, I have thought that I 

 ought to call attention to the circumstance that the mean parallel of latitude of 

 the Kuen-lun, in its whole extent, as well as in its western prolongation through 

 the Hindu Kho mountains, points to the basin of the Mediterranean and the 

 Straits of Gibraltar (Asie Centr. t. i.p. 118 127, and t. ii. p. 115118); and 

 that the subsidence of the sea-bed in a great basin which is volcanic principally 

 at its northern margin, may well be connected with those elevations and foldings 

 My dear friend of many years, Elie de Beaumont, so profoundly acquainted 



