BOUGUER'S voyage to PERU. 



297 



hills of which'ferved us as a balis to our triangles. Its ftony parts were formed like the 

 roof of a houfe, and its northern extremity being almofl quite bare of fnow, we availed 

 ourfelves, though with much labour, of the circumftance : when we had reached the 

 height, we found ourfelves covered with ice. The height of the mountain is 2476 toifes, 

 conformable to the geometrical admeafurements I have taken of it : the mercury in the 

 barometer was at 1 5 inches 9 lines, rather more than 1 2 inches 3 lines lower than on the 

 fea-lhore. A barometer had never before been taken fo high, and there is much pro- 

 bability that no perfon had ever been at the fame place ; for thefe forts of journeys are 

 attempted without a motive. The love of riches, which moves fo many people at Peru, 

 as every where elfe, fo far from leading them up fuch elevated rocks, rather urges them 

 to feek and ranfack the hollows beneath. 



It is enough that the firft bed of fnow that has fallen upon a mountain has not been 

 fubje£t to be diflblved ; that the firft and fecond Ihould be ftill lefs liable : thus, it feems, 

 the fnow muft necelTarily increafe in thicknefs, till, lofmg its fhelving form, it fmks, 

 which an earthquake may alfo occafion it to do. Maffes large as a houfe have been 

 feen to roll down, and have kept their body, although conliderably below the line of 

 the level we have mentioned, by reafon they have fallen under fhade into fome hollow 

 or deep ravine. The wind covers thefe malfes with fand, which attaches itfelf to them, 

 hence they lofe their whitenefs, and may be miftaken for real rocks, of which they par- 

 take almoft of the hardnefs. One of thefe malTes having fallen from Cotopaxi in 1739, 

 I afcertained fome months after a part of the thicknefs of the fnow on the mountain : I 

 meafured it by the aid of a micrometer, examined it in various places, and found it 

 fifty-four feet thick, although this could only be confidered as a part of the whole 

 thicknefs. I had occafion, at the beginning of the year 1743, to meafure another 

 thicknefs, though a partial one, and I found it feventy-fix feet, at the time the moun- 

 tain was vomiting torrents of fmoke and flame. 



PART III. 



REMARKS, OR PARTICULAR OBSERVATIONS, UPON THE NATURE OF THE SOIL, EARTH- 

 QUAKES, VOLCANOES, &C. 



npHE mountains around Quito appear to contain but few'metals, notwithftanding, in re- 

 mote and even at the prefent times, gold in duft has been found. The places where 

 thfey actually find a confiderable quantity of this precious metal, particularly in duft, 

 are commonly fituated much lower. On the north fide of the equator, and at two 

 degrees diftant from it, the Cordelier is perceived to have almoft loft all its height : 

 fcarcely it poffeffes one-fourth of the elevation it has in the environs of Quito; it 

 afterwards rifes again very fuddenly near to Popayan, which is fituated at from eight 

 to nine hundred toifes above the level of the fea*, but it lowers once again, not the 

 eaftern part, but the other chain on the fide of the South Sea, which, turning afide 

 to the weft, after having thrown out a branch to the eaft of the gulph of Darien, 

 takes the way of the ifthmus of Panama, dividing the Choco from the reft of South 

 America, and paiTes on to Mexico. 



* The mercury flood in the barometer at Popayan at 22 inches J0| lines j nor would it vary, as is the 

 cafe in all elevated places in the torrid zone, beyond i^ line. 



VOL. XIV. Q Q There 



