628 THE POPULAR SCIENCE MONTHLY. 



more or less deviation was experienced for almost every year of life, 

 although the small scale to which the representation is necessarily con- 

 fined docs not clearly indicate it. The most superficial examination, 

 however, must convince us that we are not dealing with accidents, 

 but with a clearly pronounced tendency in the rate of mortality, dis- 

 turbed only by minor causes. 



Leaving for the time life-insurance experience, for the wider field 

 of vital statistics generally, we have to note a most important step, in 

 the introduction of the decennial census in England in 1801, and the 

 adoption of a system of registering deaths, births, and marriages, be- 

 gun in 1836. 



The data were thus collected for constructing a mortality table, 

 embracing the whole population of England. This task was under- 

 taken by the Assistant Registrar-General, Dr. Farr, on the census of 

 1841, and is known as "English Life Table No. 1." It is based on 

 about 16,000,000 lives and 344,000 deaths. In 1863 he published a sec- 

 ond, table called " English Life Table No. 2," using the data of the 

 census of 1841 and extending the deaths to three years previous to 

 and three years subsequent to 1841. This period of seven years (1838 

 to 1844) furnished 2,436,648 deaths. Finally, in 1864, "English Life 

 Table No. 3 " was given to the public in the form of a distinct work. 

 It w^as deduced from the two censuses of 1841 and 1851, and other 

 records for the seventeen years from 1838 to 1854, embracing some 

 50,000,000 persons living and 6,470,000 deaths. Here, at length, we 

 have a life-table on the largest scale, comprising the population of a 

 whole country from birth upward. A graphic representation of the 

 same is herewith presented, as that conveys a clearer picture to the 

 mind than the reading of the numbers of the living and dying for 

 every age. 



On comparing Life Table No. 3 from ten years upward with the 

 " Ungraduated Actuaries' Experience Table No. 2," it will be observed 

 that the direction of the curve is very similar in both ; but, while the 

 one is absolutely smooth and even, the other is disturbed by the more 

 or less violent deviations already referred to. The process of remov- 

 ing these unevennesses in the line, actuaries call graduating or adjust- 

 ing. It is a very delicate and most important problem, for it involves 

 no less than the effort to determine the law of mortality, freed from 

 the accidental influences which experience has recorded. The outline 

 of this law is, indeed, clearly defined, and can be traced in every 

 table a high rate of mortality in the first year of life, decreasing 

 until the minimum is reached somewhere near the age of puberty, then 

 rising very gradually, until with old age a very rapid increase takes 

 place. But, while these general traits are well established, the details 

 are subject to continual deviations. 



We must assume that there is a fundamental law of life accom- 

 panying the organization of the human being, but that it is fre- 



