Segar. — Veracitji of Census Returns. 81 



the number of people at particiilar ages above or below the 

 normal, the number of people at the several ages should 

 change gradually and continuously from age to age. If the 

 populaiion be grouped into quinquennial age-periods, we find 

 that the numbers in the successive age-periods do change in 

 this manner. 



Figs. 1, 2, illustrate these remarks by the graphical 

 method. Fig. 1 gives the line which represents the numbers 

 returned at the several ages from 20 to 80 years in the census 

 of 1896, and also a similar line constructed by taking for the 

 central year of each quinquennial age-period the average 

 population of each year of age in that period. The ordinates 

 for these averages are measured along those corresponding to 

 the central years — namely, those ending in 2 or 7. Fig. 2 

 illustrates similarly the results of the census of 1901. 



The curve given by taking the population in quinquennial 

 age-periods offers a great contrast to the other. The absence 

 of any pronounced angular projections indicates the absence 

 of any serious tendency for the ages of people to be entered in 

 special quinquennial periods. The population, then, as ar- 

 ranged in quinquennial age-periods may be taken as being 

 practically correct, and the corresponding curve gives us a 

 fair average curve with which to compare the other. The 

 excesses entered in special years are consequently seen in 

 each case to be drawn in the main from the neighbouring 

 years. 



A comparison of the lines for the two census years shows 

 at once a remarkable resemblance m the forms of the lines 

 representing the population recorded according to each year 

 of age, indicating a remarkable general persistence in the ten- 

 dencies we are considering. The variations from the average 

 are very small until the age of 20 is reached, and this is why 

 the figures are taken only as beginning at that equation. The 

 variations are not considerable until the age of 30 years, and 

 are greatest, relatively to the population of the age concerned, 

 at 50 and 60 years. 



A careful comparison of the two diagrams will make it 

 obvious that in 1901 the variations due to erroneous returns 

 of age were considerably less than in the previous census. 

 We say a careful comparison because the mere magnitudes of 

 the variations do not, as a rule, differ greatly in the two cases ; 

 it is the variations relatively to the population at each age 

 that differ considerably. If the number of erroneous returns 

 made in 1901 were proportionate to those of 1896 they ought, 

 absolutely considered, to be much greater, because of the 

 much greater population between the ages 20 and 80 years in 

 the later of the two years. This point is also illustrated in 

 the following table, which takes the populations returned at 



6 — Trans. 



