274 On the Duration of Life in the Bengal Civil Service. [Sept. 
2. Some illustration may be necessary to explain the several positions in this 
table : thus, out of 762 writers, who were appointed during the seasons from 1790 
to 1826, in the period of 3 years, after entering the service, 4 left it, 26 died, and 
732 remained in the service at the end of the period. Again, out of 246 who were 
appointed in the seasons, from 1790 to 1800, during the period of 29 years, 85 left 
the service, 93 died, and 68 remained in the service at the end of the period. It is 
useless to extend the computation beyond the period of 30 years, for the numbers 
would be so small, that they would lead to very fallacious results. 
3. It may fairly be assumed that the mean age of writers, on their arrival in 
the country, is 20 years. For investigating the duration of life, the numberof 
those who leave the service may be thrown out of the calculation. We shall then 
have several ratios, the first term consisting of the number who enter the service 
at the commencement of any period, minus those who leave it during that period, 
or the difference between each entry in column 2, and the corresponding entry in 
column 4, and the second term, the corresponding number, who survive at the end 
of such period, as entered in column 6. These ratios may be reduced to a con- 
tinuous series, by adapting them to any convenient standard. Price’s Northamp- 
ton Tables are those most commonly in use, and we will therefore take as the 
standard 5,132, the number of persons assumed in those tables to be living, at 20 
years of age. The following will be the result : — - 
Age. 
• . 
Annual de- 
crement of 
life. 
Periodical 
Averages. 
21 
852 
850 :: 5132 
5120 
12 
- 
22 
809 
800 :: 5132 
5075 
45 
23 
758 
732 :: 5132 
4956 
119 
. 65 
24 
707 
670 :: 5132 
4862 
94 
25 
670 
628 :: 5132 
4810 
52 
26 
651 
600 5132 
4729 
SI 
) 
27 
621 
569 :: 5132 
4702 
27 
V 69 
28 
603 
545 :: 5132 
4638 
64 
29 
585 
517 :: 5152 
4535 
103 
J 
30 
564 
487 :: 5132 
4431 
104 
1 
31 
542 
457 :: 5132 
4327 
104 
i 
32 
524 
437 :: 5132 
4279 
48 
i 75 
33 
504 
415 • :: 5132 
4225 
54 
I 
34 
487 
394 :: 5132 
4152 
73 
35 
453 
360 :: 5132 
4078 
74 
36 
439 
344 :: 5132 
4021 
57 
" 
37 
424 
327 :: 5132 
3953 
68 
38 
413 
313 :: 5132 
3889 
64 
f 81 
39 
398 
295 :: 5132 
3803 
86 
40 
380 
272 :: 5132 
3673 
130 1 
41 
36 1 
252 :: 5132 
3582 
91 
1 
42 
340 
232 :: 5132 
3501 
81 
I 
43 
309 
203 :: 5132 
3400 
101 
[ 143 
44 
282 
177 :: 5132 
3221 
179 
45 
248 
143 :: 5132 
2959 
262 
46 
218 
119 :: 5132 
2801 
158 
47 
198 
98 :: 5132 
2540 
261 
48 
177 
82 :: 5132 
2377 
143 
V 190 
49 
161 
68 :: 5132 
2167 
210 
50 
138 . 
54 :: 5132 
2008 
159 J 
4. The last terms of the several proportions constitute the required table of 
the duration of life. The annual decrement is irregular, and admits of adjustment 
from the periodical averages, as entered in the last column. Beneath are exhibited, 
