528 Mr. Gompertz on the nature of the function 
mortality between the ages of 20 and 60, which appears to 
me to be the experience of the Equitable Society, is A | L j = 
3,813 — the number whose log. is (2.6051 ,0149875 x). 
This formula will give 
At the ages 
10 
20 
30 
40 
50 
60 
70 
No. of living . 
5703>2 
5403.5 
5007 
4496 
00 
ON 
3116 
* 
Differs from thel 
proposed by j 
28,2 
0 
+ 3 
0 
— 57 
0 
4lr 
In the table of Art. 12, the column marked 1, represents 
the age ; column marked 2, represents the number of persons 
living at the corresponding age ; column marked 3, the error 
to be added to the number of living deduced from the for- 
mula, to give the number of living of the table for which 
the formula is constructed; column marked 4, gives the 
error in age, or the quantity to be added to the age in column 
1, that would give the number of living in the original table, 
the same as in column 2. It may be proper to observe, that 
where the error in column 3 and 4 is stated to be o, it is not 
meant to indicate that a perfect coincidence takes place, but 
that the difference is too small to be worth noticing. 
