154 Royal Society : — Mr. Ellis on the Corrections for 



Ex. 5. Height of St. Ceruues, in the Canton de Vaud, on the 

 road from Paris to Geneva, lat 46°. {Ann. Meteor, de Fr.1849, p. 50.) 



B 729-71 M' 21\5 A' 21-8 H x 408 



h 67073 m' 18"8 a' 18*8 



500-0 



B + 6 1406-44 2-7 



B-b 5298 



Xl-3 500)5406 



X 16000 q 35 1-0812 



— •0001 lat. 46° 



1406-44)847680-00(602-7 



-•9 p 1-0811 



598-3 

 601-8 x 1-0811 p 



-3 5q -- = 



646-8 



app. diff. oflevel 598'3 408-0 H x 



+ •2 for 1000 



h y 1055 metres. 



Table I. 



NOTATION (capitals, lower station ; small letters, upper station). 



B. b units of length of any kind, height of barometer. 



B', b' the same reduced to 32 ' Fahr. 



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



M, m ,, ,, M', m\ ,, ,, M", m" ,, ,, temperature of msroury. 



H, k feet, H v h x metres, H 2 , h 2 toises, height above sea. 



V, v „ Y v v x „ V 2 , v 2 „ correction for height. 



R ,, ~R X ., B 2 ,, mean radius of earth. 



log R=7-3199534, log K, =6-8039605, 'og R 2 =6-5141407. 



L degrees, mean latitude of the two stations. 



*;=-0l)0039 . (M-m) = -00007 . (M'-m')= -000088 . (M"-m"). 



T=A+a+836; T'=A'+a'+500; T"=A"+a"+400. 



W=log B-log b-t=log B'-log b'. 



log G=log 60309-19 -log 900-log (1- -00263 cos 2L). 



log G 3 =log G+9-83619-10 



log G' =log a+0-25527 

 log G"=log G+0-35218 

 log G, = log G4-9484Q1-10 

 log G 2 =log G4-9-73928-10 



log G t = log G-+9-19419-10 

 log G-=log G+9-44946-10 

 log G 6 =log G+9-54637-10 



1 metre =3-28090 feet, 1 t;ise =6-39459 feet, 1 toise =1-94904 metres, 

 log 3-28090= -51599, log 6-39459= -80581, log 1-94904= -28982. 



FORMULA. 



Result. Temp. 



Feet Fahr. h =W.T. G 4-H +v -V 



Gent. =W.T'. G' 4-H +v -V 



Reaum. =W.T".G"+H +v -V 



Metres Fahr. h x = W.T . G x + H, + v x - V x 



Cent. =W.T'.G 2 +H 1 +v 1 -V 1 



Reaum. = W.T".G 3 4-H^-f^-V. 



Toises Fahr. h 2 = W.T . G 4 +H Q + v 2 - V 2 



Cent. =W.T'. G 5 +H;-|-v 2 -V 2 



Reaum. =W.T".G 6 4- H 2 +v 2 -Y 2 



