STUDIES IN STATISTICAL REPKESENTATION. 



99 



The average population during that period was 3,995,800, 

 hence the average daily number of suicides per million of 

 inhabitants is obtained by dividing the figures in (4) by 

 3*9958. The results are shewn in the following table : — 

 Daily suicides per million inhabitants. — Equalised months. 



Dec. 



•3451 



Jan. 



Feb. 



Mar. 1 April May 



June 



July 



August 



Sept. 



Oct. 



JNov. 



3589 



•3714 



•3349 -3359 |-3096 



•2838 



•3008 



•3256 



•3071 



•3531 



•3233 



-^-[•3589 + -3451] == '3291 



By addition, as before, 



The determination of the constants is effected as in the 

 case of the temperature curve. The resulting frequency is 

 = 0*3291 + 0*0354 sin (x + 72° 4') - 0*0117 sin 2 (x + 73° 22') 

 + 0*0031 sin 3 (x + 12° 49') - 0*0142 sin 4(aj + 40° 52') 



-0*0131 sin 5 (a + 0° 16') + *0104 sin Qx. 



12. Reduction of epochal angle to days —It is sometimes 

 desirable to reduce the epochal angles of an annual series 

 to days, particularly in the calculation of " lag." See § 13. 



Since an angle of 360° corresponds to 365*2422 days, the 

 following approximate relation holds between D the number 

 of days and g the epochal angle expressed in degrees 



(52)... B = g [1 + joo"+ 200 " 2000 + 20000 + 100000 

 which gives 365*2416. 



As many terms can be used as are necessary, and the 

 result can frequently be written down by inspection. As a 

 rule it is sufficient to stop at the term ~. 



Another convenient relation between D and g is 



(52a)... D = g 



1 + A. 



70 



1 



7000 100000 

 which gives 365*2421, and in most cases it would be sufficient 

 to stop at the term — . 



13. Determination of "lag" in correlated phenomena.— 



Given two periodic series of the same periodicity, viz., 



