CHAP. III. THE ASCENT OF CHIMBORAZO. 65 



ridges of this mountain were originally lava-streams. Their 

 normal appearance has been largely modified ; much is covered 

 up by snow, the exposed portions have been greatly decomposed 

 and eroded, and lie almost buried underneath their own ruins. 



After these convenient snow-beds were traversed our ridge 

 steepened — both as regards its arete, and the angles of the 

 slopes on each side ; and became in j^art covered by pure ice, 

 and partly by ice mingled with small stones and grit. When 

 this conglomerate was hard frozen, it enabled us to ascend with- 

 out step-cutting ; but the debris often reposed uncemented on 

 the surface, and rendered caution as well as hard labour neces- 

 sary. I found here, scattered over about fifty feet, rather 

 numerous fragments of partly fossilized bones. Sir Richard 

 Owen, to whom they were submitted, pronounced them to be 

 " the bones of some ruminant.^' The unhappy ruminant most 

 likely did not come there voluntarily, and I conjecture that it 

 was conveyed to this lofty spot, either entire or in part, by a 

 condor or some other bird of prey, to be devoured at leisure. 



At 7.30 a.m. we arrived at the foot of the lower series of 

 the Southern Walls of Ohimborazo, and the termination of the 



"The specimen taken near the third camp, and representing the rock which 

 prevails throughout the ridge by which the first ascent was made, is a rock macro- 

 scopically related to the one last described, but is a little redder in colour, more 

 vesicular in structure, and with slightly larger crystals of felspar (up to about 

 ith inch diameter). So far as the base and its included microliths are concerned, 

 there is little to add to the preceding description, except that a dusty ferrite is rather 

 abundant, as the colour of the rock would lead us to expect, the larger crystals of 

 felspar do not materially differ from those already described, hypersthene is abundant, 

 undoubted augite being rare, and there are two or three small crystals of a strongly 

 dichroic hornblende. Also one or two crystals of what appears to be an iron mica. 

 The predominance of hypersthene entitles this to the name of a hypersthene-ande- 

 site."— Prof. T. G. Bonney, F.R.S., Proc. Roijal Soc, No. 232, June 19, 1884. 



The whole of the rocks collected upon this journey were submitted to Professor 

 Bonney, by whom they -were described in the Proceedings of the Royal Society in 

 a series of five papers (Jan. 31-Nov. 27, 1884). Prof. Bonney has also favoured 

 me with the summary which will be found at pp. 140-143 of the Supplementary 

 Appendix to this volume. 



K 



