( 209 ) 
PART V. 
DETERMINATION OF HEIGHTS. 
By Francis Galton, f.r.s. 
By the Temperature of Boiling Water . 
Enter Table I., p. 210, with the boiling-point at each of the two 
stations, and extract the numbers that stand opposite to them in the 
column headed “ Altitude, &c/’ The difference between these numbers 
gives the difference of height between the two stations, supposing the 
mean temperature of the intermediate air to be 32° Fahr. The correction 
for the temperature of the air, when it differs from this value, is given in 
Table II. We take the mean * of the thermometers (exposed in shade) 
at the upper and lower stations, and we enter Table II. with that mean 
value, and the number that stands opposite to it, in the column headed 
“ Multiplier/’ must be multiplied with the results obtained from Table I. 
Thus:— 
At station A the boiling-point = i 95 °'i, tabular number = 9040 
„ B „ 2 io°* 3 , „ = 887 
Approximate difference of height = 8153 feet. 
To correct for temperature of intermediate air 
At station A, temp, of air = 65 ° Fahr. 
)3 j) — 73 jf 
2 ) 138 
69 = mean temperature of intermediate air. 
* This represents more nearly the average temperature of the intervening 
column of air than any other value that can easily be specified. But it is only 
an approximation of the truth. 
VOL. I. 
P 
