[ 08 ] 

 XIII. Proceedings of Learned Societies. 



110YAL SOCIETY. 



[Continued from vol. xxvi. p. 548.] 



March 26, 1SG3. — Major-General Sabine, President, in the Chair. 



Hj^HE following communications were read: — ■ 

 JL M Researches into the Chemical Constitution of Narcotine, and 

 of its Products of Decomposition." — Part I. By A. Matthiessen, 

 F.R.S., and George Carey Foster, B.A. 



Postscript to a Paper read January 15, 1863, " On the Formation 

 of Fibrin from Albumen." By Alfred Hutchison Smee, Jun. 



" On a Simple Formula and Practical Rule for calculating Heights 

 barometrically without Logarithms." By Alexander J. Ellis, B.A. , 

 F.C.P.S. 



The following formula and table for calculating heights barome- 

 trically without logarithms will be found to give the same results 

 as Laplace's formula up to 30,000 feet, and the table can be readily 

 extended if required. Let 



L degrees be the mean latitude of the two stations, 



I =2-6257 cos 2L, G=l + 0'0026257 cos2L, 



R= 20888629, the number of feet in the earth's radius. 



H feet, its height above the sea, H"=H 2 -t-R, 



B units of any kind, height of barometer, uncorrected, 



B' „ ^ „ „ „ „ , corrected, 



A deg. Fahr., A' deg. Cent., A" deg. Reaum., temperature of air, 



M „ „ , M' „ „ , M" „ „ , „ of mercury. 



At the upper station. 



h, h", b y V, a, a\ a", m, m', m" in the same sense. 

 Then 



L U + 6 V ; J 900 



+ '001.(A-H)M-A"-H", (a) 



where M— m=0, when B, b = W, V, and 



2-35 (M-m)=4-23 . (M'-«i')=5-'29 . (M"-m") 

 836 + A+a _ 500+A! + a f __ 400+ A" + g" 

 900 " 500 ~400 " 



The numbers c, 1, h", H" are to be taken from the table on the 

 next page, as will appear by the following examples. 



