BOUGUER*S VOYAGE TO PERU. 289 



mftant. We therefore became fenfible it would in every refpe£l be more to our ad- 

 I'antage not to make the triangles of our meridian fo high, and that we ought ordi- 

 •narily to be fatisfied with placing our fignals upon the hills at the bafe of the rocky 

 pyramids. But notwithftanding this very neceflary precaution, nothing incommoded 

 us in our labour fo much, as the fudden alterations of heat and cold which we expe- 

 rienced from one moment to another, every time, however inconfiderable, we afcended 

 or defcended. 



M. Condamine and myfelf had already once more afcended the mountain, but 

 with no other defign than to examine the flation, v/hen we were obliged inflantly to 

 defcend ; we were furprifed by a ftorm, the wind had no particular direftion, but blew 

 from every quarter at the fame moment upon us. The thunder drove the hail-ftones 

 horizontally againft us, and was fcarcely louder than the flafh fcom a gun, which im- 

 preffed the idea upon us, that upon the moft elevated mountains the report of it would 

 not be at all heard. We had every opportunity during the three weeks we were fta- 

 tloned here, to reform this firft opinion ; and we have been a great number of times 

 fmce upon other mountains, where we have heard the moft terrible rolling of thunder, 

 fometimes over our heads ; at others, beneath us. It is not to be difputed that the 

 claps of thunder are fometimes very weak ; fuch as they are generally when the light- 

 ening is feen and no noife follows. We do not hear them below ; thefe are happily 

 ftrokes without effeft, which may arife from many caufes, and often from the great 

 diftance at which we may be from them. At the time I have juft mentioned, when 

 upon the height, we were in the very focus of the ftorm, but apparently the inflam- 

 mable matter had colleded in too fmall a quantity. 



The higheft ftations, in our work of the meridian, have always occafioned us the 

 moft trouble. The moft elevated ftation we availed ourfelves of for our triangles, is 

 two thoufand three hundred and thirty-four toifes above the fea, and is named 

 Sinazahuan ; it forms one of the fummits of the mountain of Afouay, which divides the 

 jurifdi£lion of Riobamba and Cuenca. It will furprife you to be told the Incas have 

 carried a road over this height, which they are in the habit of daily frequenting ; but 

 they are careful to chufe the weather ; for if they have the misfortune to be caught in 

 a ftorm, mingled with hoar or fnow, they run a rifk of never returning more. We 

 fortunately carried a change of tents along with us ; ten or twelve of the days we were 

 ftationed there, we had to fubftitute the one for the other three times fuccelTively. So 

 greatly were they alarmed on our account at Atun-Cagnor, a town three or four 

 leagues diftant, that public prayers were offered up for us. 



Every variety of weather we have had whilft amid thefe mountains, has fufficlently 

 fatisfied us how much certain philofophers have been miftaken, who have conceived 

 the clouds of a nature different from fogs. The clouds have frequently not afcended 

 to us, they have been five or fix hundred toifes below us, and have veiled the valley 

 from us, while the inhabitants of the plain could not difcern the fky : at other times 

 thefe clouds having lefs weight, have rifen higher, and become to us a fimple fog in 

 w^hich we found ourfelves involved. When I have noticed them very much above me, 

 they have always appeared very white : I do not know what better I can compare them 

 to with regard to the colour and form they then prefented, than to heaps of cotton 

 touching each other, whofe union prefents a wavy furface. With refpeft to the colour, 

 it is precifely the fame as with water and glafs ; glafs we know lofes its tranfparency when 

 pulverifed, and when looked on at its brightelt fide, appears to have all the whitenefs 

 of fnow. So it is with water when reduced to very fmall particles, or almoft imper- 

 ceptible drops in the clouds or fogs. If thefe fmall drops are nothing elfe than fmall 



VOL. XIV, r p hollow 



