80 G. H. KNIBBS. 



Example — For the decennium 1900 to 1909 in the Com- 

 monwealth of Australia the following average numbers of 

 persons, viz., those shewn on line (1) committed suicide 

 per diem in the successive months of the year. The rate 

 of growth of the population assumed to be linear, was 0*0177 

 per unit per annum ; hence the correcting factor is 1 ± 

 0*0177.*, where x is the interval. Making this correction 

 the number in line (2) is obtained. 



Number of Persons daily committing suicide in Australian Com- 

 monwealth, decennium 1900 - 1909. 



(i) 



(2) 

 (3) 

 (*)t 



* 



Jan. 



Febr. 



March 



April 



May 



June 



1-423 



1-479 



1-335 



1-340 



1-239 



1133 



1-435 



1-489 



1-342 



1-345 



1-242 



1-134 



+ •054 



-•147 



+ •003 



-•103 



-•108 



+ •065 



1-434 



1-484 



1-338 



1-342 



1-237 



1134 



July 



August 



Sept. 



Oct. 



Nov. 



Dec. 



1-200 



1-303 



1-230 



1-416 



1-300 



1-390 



1-199 



1-300 



1-225 



1-409 



1-291 



1-378 



+ •101 



-•075 



+ •184 



-•118 



+ •087 





1-202 



1-301 



1-227 



1-411 



1-292 



1-379 



(1) 



(2) 



(3) I 

 (*)t/ 



Note. — * For meanings of lines (3) and (4) see Section 3. f(4) 

 denotes the monthly average of the numbers of persons daily committing 

 suicide for months of equal duration and a constant population, viz., 

 the mean population for the year. 



The correction is thus, 1 - kx, in which x is interval of 

 time from the end of 30th June, expressed as a fraction of 

 a year and is negative if earlier than that date, positive if 

 later. This correction can frequently be made by inspection. 



3. Correction for unequal length of months.— There is 

 another correction, however, which it is necessary to make, 

 viz., that due to unequal length in the different months in 

 the year. If months were equal in length then the aver- 

 age would be free from error, and would give either the 

 a of the formula, or a multiple thereof. The table here- 



