These facts have their bearing upon the already noted statement that the summer months show a preponderance of homicide.
Fig. 4.
Barometer.—Fig. 4, disassociated from the others, shows but little. Naturally we should not look for very marked effects from variations of an inch or less in the barometric readings, when in the course of a journey from the sea level to Denver a change of six inches is brought about, and in going from the same point to the summit of Pike's Peak one of nearly twelve inches without producing any marked emotional abnormities, but we must take into consideration the fact that sudden barometric variations generally accompany or more frequently precede other important meteorological changes. In the latter case, though they might be the primary cause of factors considered in this study, they themselves would fail to show upon the tables.
Fig. 5.
Fig. 6.
Humidity.—This figure (Fig. 5) indicates in a very decisive manner that states of low relative humidity, as shown by both maximum and minimum readings, are conducive to excesses in both the classes of crimes studied. For instance, for maximum humidities between ten and twenty the proportion of actual crime to that expected is 1:0.1; between twenty and thirty (suicide), 11:1; between thirty and forty, 9.5:4.5; between forty and fifty, 15:8. The maximum curves show somewhat the same general relation though not with quite so marked divergences. To one who has experienced the general low humidities of our Colorado altitudes (Denver is one mile above the sea level) this result is not surprising. There is no doubt that a nervous tension much in excess of that common in the lower altitudes exists, due in part, perhaps, to the deficiency in barometric pressure and a consequent effect upon the respiratory processes, but probably, as shown by these curves, more largely to the dryness of the atmosphere, as indicated by low humidity. I hope at some future time to verify or disprove this supposition by a comparative study made at some lower altitude.
Character of the Day.[D]—Fig. 6 shows the relation between the expectancy of crime, based upon the actual per cents of cloudy, partly cloudy, and clear days (records of nineteen years), and its actual occurrence. The disagreements are very slight, although a slight excess of murders is shown for cloudy days.