Mathematical Collections of Pappus. 21 
likely to do so, as there was no suspicion in his time of any va- 
riation. If this were so, he would have had BC : AB : : sin. & : 
cosin &>::!: n — : : 1 ; cotan and I : cot 23° BY 20" : : 10 : 22.6. 
sin a 5 
Now, this is so nearly the ratio of 10 to 23, that he might have 
adopted the whole numbers for his purpose, without any 
thought of indicating a difference in the obliquity from that which 
had been used by Ptolemy. 
Upon the whole, then, I think we may fairly conclude that 
no alteration is required, and that none can be admitted in the 
original text. And this supposition having been disposed of, 
nothing can be mose just than the following description of the 
passage, which M. Delambre himself gives in the other part of 
his remarks : 66 Pappus nki nullement en vue de nous donner 
une determination bien juste de Pobjiquite ; pour prouver une 
proposition sur la vitesse du mouvement du soleii, il n’a besoin 
que d\m apercu bien grassier de la grandeur du tropique. 
C’est ainsi q\i Archimede, dans son Arenaire, pour etablir son 
calcul, suppose au rayon de la sphere des fixes une grandeur 
qukl n’a pas pretend u donner comme exacte a beaucoup pres. 
Le temoignage de Pappus n’a done pas ici plus de poids que 
n’en aurait celui d 1 Archimede dans la question de la parallaxe 
des etoiles.” 
JU 
Oxford, ) 
April 1821. j 
Art. IV .-—Account of the Atush Kudda , or Natural Fire 
Temples of the Guebres , formed by burning Springs of 
Naphtha , with a Notice respecting the Naphtha Wells in 
Pegu *. 
The ancient sect of the Guebres or Parsees, distinguished 
from all others as the worshippers of Fire, derived their opi- 
* This article has been drawn up from information contained in the Travels of 
FoTster, Hanway, Rieberstein, Cook, Kinneir, and Hiram Cox, and from a paper 
written by M. J. J. Virey, and published in the Journal de Fharmacie for May 
1820, vol. vi. p. 209.— D. B* 
