INFLUENCE OF THE WEATHER UPON CRIME. 655 



mui'ders, one hundred and eiglity. It mav be noted that this num- 

 ber of suicides, for a city averaging hardly one hundred thousand 

 inhabitants for the fourteen years, is largely in excess of the rate 

 recorded for American cities, but it must be remembered that some 

 of these were unsuccessful attempts, and also that the social condi- 

 tions of Denver tend to swell the number — containing, as it does, so 

 many disappointed in the last struggle for health. 



Fig. 1 shows the occurrence, in per cent, of crimes of both the 

 classes considered for each month of the year, together with the 

 monthly meteorological means, comjDuted from the records for nine- 

 teen years. The expectancy curve in the occurrence table is based 

 upon the supposition that the months of the year are all of the same 

 length, and that the numerical expectancy would be one twelfth, or 

 eight and a third per cent for each. It will be seen that the crime 

 curves are for the most part below the expectancy for the winter 

 months, and above it for the summer (except for April, and suicides 

 for June), showing the maximum for the latter class in May and 

 for murders in March. Morselli shows * that for most European 

 countries suicides are at the maximum in June, though a consider- 

 able number show that condition for the later spring months. A 

 study of the general meteorological means, sho^vn upon the same 

 plate as the occurrence table, fails to indicate any good reason for 

 irregularity of the crime curves. The " month " columns read from 

 the top to the bottom of the chart, and by following that for May, for 

 instance, which month shows the maximum for suicide, we find that 

 the meteorological condition for each class of data is about halfway 

 between the extremes for that class for the year, while for January 

 (minimum suicides) each class is by far more divergent. Yet a 

 mean, like those considered in this table, is but the average of the 

 extremes, and those months which show great per cents of crime 

 also present great extremes of condition, which fact, interpreted in 

 the light of those disclosed by the charts yet to be considered, make 

 the occurrence curve more explicable. 



"Wind. — An explanation of the various curves in Fig. 2 may 

 serve for the series following, so I give it somewhat in detail. The 

 vertical distances from the base line indicate per cents, and the dis- 

 tances from left to right, divided into columns, the maximum veloci- 

 ty of the wind per hour for the days tabulated. In the " normal " 

 curve every day for five years was considered, and it was found 

 that seven per cent of the days for that period showed a maximum 

 velocity of between one and ten miles (first column), forty-eight per 

 cent a maximum velocity of betwe'en ten and twenty miles (second 

 column), nineteen per cent a maximum velocity of between twenty 



* Suicide, International Science Series. 



