422; Mr. A dams on [Jij n e , 



S being the specific gravity as before. If, therefore, t be the 

 tension of vapour at the temperature F^ and S' its specific gra-» 

 vity, we have 



^ F' + 448 , or,, o ^ r' F + 448 



. ^ ^ fT-4-48 ^ ^ ^^ S : S = S X - X ^r;^. 



Hence it is impossible that the specific gravity of vapour can 

 be' accurately proportional to its tension ; and this follows not 

 from any new principles, but from what has been allowed by 

 evjery philosopher. We may, therefore, safely affirm, that the 

 table of the specific gravity of aqueous vapour Dr. Thomson has 

 cotnputedin his present paper for the rectification of the specific 

 gravity of gases, cannot be correct. 



If, as Gay-Lussac makes it, the specific gravity of vapour at 

 212° be A, that of common air at the same temperature, then the 

 specific gravity of the vapour in any gas over water at the tem- 

 perature F^ will be 



5 t' 660 55 t' 



77 X 7— X 



8 30 F' + 448 4 (F' + 448)' 



supposing that the tension at 212°, and the elasticity at F', are 

 each 30, and the specific gravity of the atmosphere at 212° unity. 

 Should the specific gravity of the vapour be required when that 

 of our air is unity at any other temperature J\ it may be had by 



multiplying the preceding expression by *^-|r—, which will make 



It 



660 



(/ + 448) . t' 



48 . (F 4- 448) 



The atmosphere at 60° being 1, the specific gravity of vapour 



at 32° = ^T^ = -00441, which exceeds -00314 given by Dr. 



Thomson in the ratio of 8 to 11. In cases far above 212°, the 

 difference will be much greater. J. Herapath. 



Article VIII. 



■Ow Right Angled Spherical Triangles. By Mr. James Adams. 



(To the Editor of the Annals of Philosophy,) 



SIR, Slonehouse, near Plymouth, March3, 1829. 



If, in your opinion, the following demonstrations of the theo- 

 rems relating to right-angled spherical triangles independent of 

 supplementary triangles, merit a place in the Annals of Philoso- 

 j}hy, their insertion therein will much oblige, 



. Your humble servant, . ^. 



James Adams^ 



