measurement of Snowdon by the Thermometrical Barometer. 297 
By the use of these logarithms, the series of barometrical 
heights corresponding with each degree of Fahrenheit, cal- 
culated from 30 inches at 212 0 , downward to 202°, and car- 
ried upward to 214 0 , will be found in the following Table I. 
in the - fifth column of which the difference of the logarithms 
of the barometric column, which corresponds by a known 
law with the mumber of fathoms of elevation, is multiplied 
by 6, to give the feet of elevation which produces the suc- 
cessive depression of the boiling point one degree of Fahren- 
heit ; and the 6th column gives the total elevation, reckoning 
from the station where water boils at 21 a* 0 , to any other sta- 
tion where the boiling temperature is at any degree between 
202 0 and 214 0 . For the differences between each degree, the 
elevations may be taken with sufficient accuracy by simple 
proportion. 
Table I. 
I 
2 
3 
4 
5 
6 
Heat of 
boiling 
water. 
Correspondent 
height of 
barometer. 
Logarithm 
of height of 
barometer. 
Difference 
of the 
Logarithms. 
Difference of Loga- 
rithm multiplied by 
six equal feet. 
Total feet 
from 212 
degrees. 
214 
213 
212 
211 
210 
209 
208 
207 
206 
205 
204 
203 
202 
31,2395 
30,6149 
30,0000 
29,3948 
28,7993 
28,2133 
27,6367 
27,0695 
26,5 I I 5 
25,9627 
25,4230 
24,8923 
24>3704 
4947044 
4 8 593 2 4 
4771213 
4682712 
4593820 
43 ° 453 8 
4414865 
4324802 
4 2 3434 8 
4143504 
4.05 2270 
3960645 
3868630 
87720 
881 1 1 
88501 
88892 
89282 
89673 
90063 
90454 
90844 
91234 
91625 
92015 
526,320 
528,666 
5 31,006 
533 > 35 2 
535,692 
538,038 
540,378 
542,724 
545,064 
547 * 4°4 
549,750 
552,090 
1054,986 
528,666 
O 
531,006 
1064,358 
1600,050 
2 I 38,088 
2678,466 
3221,190 
3766,254 
4313,658 
4863,408 
5415,498 
