Page:Popular Science Monthly Volume 28.djvu/693

Rh —We next observe that, of the three observations, the air carries the most moisture at the 9 [[Category:]] one, an amount which is, on the average, only slightly in excess of one half of saturation; that the midday air is quite dry, giving a mean for the eight months of 41·5 of saturation; and that at 5 the average of humidity is 45·5 per cent of saturation—all of which simply strengthens what we have previously said in regard to the dryness of the Colorado climate.

—As regards the temperature we learn that, as we should expect, the coldest registrations occur in the months of December, January, and February; and that even in these months an invalid can be out of doors, so far as this factor is concerned, from 9 to 5

In considering this question several things must be borne in mind. In the first place, these registrations arc those of thermometers placed in a "shelter-box," and consequently in the shade, with a northern exposure, and ten feet above the roof of a six-story building, and so they are not influenced by the direct solar rays, which are very powerful. It must further be borne in mind that these registrations do not "feel" so cold as similar ones would in a dense and damp air, like that of either New York or Boston, owing to the fact that we have mentioned, viz., that a thin, dry air does not rapidly rob the body of its heat, and so the skin does not become chilled so rapidly as at sea-level with the same temperature.

As a matter of fact, the writer remembers that he went around at midday the greater part of the winter without an overcoat. He recalls sitting with open windows in the very heart of January, and was accustomed to seeing people sitting out of doors basking in the sun.

And right here he is willing to acknowledge that there is a grain of truth in the criticisms broached with reference to our extremes of temperature, both diurnal and monthly. They do occur, but then only rarely (that is, such extremes as have been quoted against us), and, when they do come, they are due to high temperatures in the daytime and very low ones at night—conditions which can occur only in thin, dry airs like our own.

The night temperatures are uniformly cold; but they do not affect the invalid, because he should at that time be housed, where he can regulate the temperature to suit himself, and our tables show conclusively that the hours of sunshine are warm and comfortable.

We regret exceedingly that we are not able to give the "sun-temperatures," as they would convey a more correct impression of the warmth of our midday, as every person knows who has tried the difference between the shady and sunny side of the street in our city. But we know of no data on that point, and our Signal-station is not as yet supplied with a sun-thermometer.

—As regards the winds, these tables prove that in Denver at 9 the prevailing direction is from the south, and that at 6