OBSERVATIONS OF UNDERGROUND TEMPERATURE. 439 
ph a ee 
es v=A,+ Pye ot Te gin (297 +E,—2@ y=) +P,e” WE (408 —@ [2a + &e. 
a 
oe [nxe 
Plots sin (ne +E,—2 a) F 
% In this equation x denotes the distance below any assumed horizontal plane. 
Let the plane pass through the bulb of one of the thermometers ; then the general 


Qn + Ep -2£ TE 
Jz 
Pa, Tk in ( ae 
Rife 
er 
; T* to 1, while the quantity E, is diminished by the amount 
| am Whence the equations 
eonloge Bir 2 APk al fieee 
in the ratio of ¢~ 


Lv ve 
