OBSERVATIONS OF UNDERGROUND TEMPERATURE. 433 
The application of the process above indicated to the determination of A, B, 
A, B, for the 3 feet thermometer is subjoined. 
Il. . IV. 
Products. | III.+I1V. Products. 
Temperatures | Temperatures Last two 
of first 6 of last 6 Nos. in III. 
months. months. reversed. 
40°57 52:70 
39°64 53°82 +7:24 

40°31 52°75 + 0°35 
42°45 49-15 
45:87 45°62 
49°86 42-62 



| re Dn oO | Multipliers. 

= | So DN | Multipliers. 




























——- Vee ve "a Products. again. 'e Products. 
First Half of | Last Half of FI a a 
(I. +11.) (1. +11.) S| S 
93°27 91:60 +1:67 i + 1:67 1-67 0 00 
93°46 91-39 + 2:07 S, | +#1:035 + 2:07 S, 
93-06 92-48 20507, | —S,,-)— 0-290 + 0-58 7 "Ae ie 
6) | +2:415 6) | +2:295 
A,=| + °4025 B,=| + +3826 
= 

A,=mean of all the numbers in I. and II]. = 46:27. 
There are in all four thermometers, their bulbs being sunk to depths of 3, 6, 
12, and 24 French feet respectively below the surface of the ground. The means 
of their readings, in degrees Fahrenheit, for each calendar month, on the average 
of the seventeen years 1838-1854, are as under :— 





Depth of - 
Ther- Jan. Feb. Mar. | April. | May. | June. | July. | Aug. | Sept. Oct. Nov. | Dec. 
mometer. 













3 feet | 40-57 | 89-64 | 40-31 | 42-45 | 45-87 | 49-86 | 52-70 | 53-82 | 52-75 | 49-15 | 45-52 | 42-62 
6 feet | 43-59 | 42-35 | 42-00 | 42-79 | 44-65 | 47:23 | 49-71 | 51-31 | 51-54 | 50-11 | 47-81 | 45-48 
12 feet 45-06 | 44:68 | 44-88 | 45-63 | 46-84 | 48-07 | 48-96 | 49-27 | 49-02 | 47-94 
24 feet 47-63 | 47:39 46-79 | 46-59 | 46-55 | 46-69 | 46-97 | 47-31 | 47-61 | 47-79 















VOL. XXII. PART II. Der 

