Dr. Klrivan on the primitive State of the Globe. 15 



limit at which they could be found, namely 9000 feet, for 

 that thofe which 1 quoted as proofs of a fubfequent deluge, 

 found, according to Don Ulloa, at the height of 14,250 feet 

 in Peru, were in reality petrified. To this account, as it was 

 only a hearfay report of Gentil, who had it from Don Ulloa, 

 I own I did not give full credit; at Icaft I thought the cir- 

 cumliance of their having been petrified and imbodicd in a 

 rock not probable : fiuce that time I have met with a work, 

 compofcd by Don Ulloa himfelf^ entitled Memoires Vhilofo- 

 pbiqucs, Hijioriques i:t Phyjiques, in the firll volume of which, 

 p. 34 and 364, the fa<Ft of the fliells being petrified and im- 

 bodicd in a rock is fully ftated and confirmed : but 1 (hall 

 here fatisfai^orily prove that the height at which they were 

 found did not exceed, nor even equal, 9000 feet above the 

 level of the fca; and, fecondly, that they were left there by 

 a deluge that fuccceded the cmerfion of land from the pri- 

 maeval ocean. 



Fir{l, Gentil tells us, il/,'ra, Var. 1771, p. 439, in 8vo., 

 that thefc fliells were found on a mountain near Guancave- 

 lica, a fmall town or village between 13^ and 13° fouth lati- 

 tude, which mountain, he fays, is far from being one of the 

 higheft of the Cordeliercs ; and that on the fpol in which 

 the (hells were found, the mercury in the barometer ftood at 

 the height of 17 inches one line and 4- -~ 37,103 inches; 

 froin which he infers that this fpot was elevated 2200 toifcs 

 over the level of the lea, — 13,869 tnglifh feet. This height 

 I fliall now fliow to have been iallcly elti mated. 



Don Ulloa tells us, p. 34 ot the abovemcntioncd woric, 

 and Gentil repeats after him, that, at the village of Guanca- 

 velica, near but fomcwhat below this fpot, the mercury (lood 

 jit the height of 18 inches one line and half. Now Bouguer, 

 Figure dc la Terre, p. 36, exprefsly fays that Quito is ele- 

 vated from 14 to 1500 toifes only over tlie level of the fca, 

 and is the higheft inhabited part of the globe : Guancavclica, 

 therefore, which is inliabitcd, and mufl; have been well known 

 to Bouguer, cannot be fo high as Quito. Quito was geo- 

 metrically meafured, Guancavclica was not. 



Bouguer alfo tells us, ibid, in note, that the mercury at 

 Quito {lands at the height of twenty inches and one line: 

 how then is it poliible that it (liould (iand at eiglUeen inches 

 and one line at Guancavclica, whicli mult be much lower, if 

 the barometer were not ill coiiflriK^K'd ? No ditfercnre of tem- 

 perature between Quito and Guancavclica could caufe fuch 

 an enormous dilfc-rence as two inches in the mercurial height. 

 The an ajid iieceflTity of freeing barometers fiom air were not 



generally 



