the decrement of human life. 285 
tables, for example, exceeding those of the Northampton by 
one half in the former, and by one tenth only in the latter. 
The proportion of Mr. Finlaison’s tontines also stands as 3 
to 4 in the first, and as 7 to 8, or 8 to 9 only in the second : 
the latter comparison giving a much fairer practical estimate 
of the comparative longevity, indicated by the tables, than 
the former. 
Another mode of easily appreciating the regularity and the 
analogies of different tables is, to construct a diagram, in the 
form of a curve, of which the absciss represents the age, and 
the ordinates the corresponding decrements of life. (Plate XI.) 
The inspection of such a diagram is sufficient to convince us 
of the great irregularity of the Carlisle tables of mortality, 
which must obviously have been formed, as they confessedly 
were, from observations on a very limited number of indi- 
viduals, so that they exhibit a succession of different climac- 
terics, after which the mortality is diminished, while about 
the age of 74 the curve that represents them towers to an 
incredible height, affording an expectation of longevity which 
some of the strongest advocates of those tables have aban- 
doned in their practical applications, since they take their 
estimate of life, in advanced age, even lower than it is re- 
presented in the Northampton tables. 
It appears therefore to be highly probable, that the fairest 
basis for general computations, to be applied throughout 
Great Britain, may be obtained by a proper combination of 
the tables of Northampton, which have been long known and 
very generally approved, with the Carlisle tables, corrected 
however in their extravagant values of old lives, by some 
other documents ; and with the mortality of London as 
mdcccxxvi. P p 
