OBSERVATIONS OF UNDERGROUND TEMPERATURE. 437 
For THE ANNUAL TERM. 















Thermometers Ps 
compared. Tk Tk 
3 feet and 6 feet. 35 3 ‘117 .o9 3 ‘130 
8 feet and 12 feet. 1:05 9 117 Pl 123 
3 feet and 24 feet. 2°44 21 ‘116 2°42 21 ‘115 
6 feet and 12 feet. ‘70 6 117 72 6 120 
6 feet and 24 feet. 2:09 18 "116 2°03 18 113 
12 feet and 24 feet. 1:39 12 116 1:31 12 "109 
Means, 





Thermometers 
compared. 
3 feet and 6 feet. 
3 feet and 12 feet. 
3 feet and 24 feet. 
6 feet and 12 feet. 
6 feet and 24 feet. 
12 feet and 24 feet. 



Means, 
Quotients by 4/2, 


The results deduced from the annual term agree the best among themselves, 
and are the most reliable; the coefficients P, of the half-yearly term being very 
small, and varying considerably from year to year. Notwithstanding, the mean 
values -113, :116 of ae deduced from the half-yearly term, agree very well with 
the values °1165, ‘1183 from the annual term. Professor THomson’s results from 
the temperatures of the thirteen years 1842-1854 were :— 
By Phase. By Amplitude. 
For the annual term, . 3 : -1156 "1160 
For the half-yearly term, . : 08861 11133 
we 
—these numbers being the values of the function obtained from the coeffi- 
N Tk 
VOL. XXII. PART II. dU 
