Rensselaer Union, Volume 7, Number 47, Rensselaer, Jasper County, 12 August 1875 — Winds and Storms. [ARTICLE]

Winds and Storms.

Mr. Colding lias communicated an interesting article on winds and storms to the Zeitschrift of the Austrian Meteorological Society. After explaining the effect of the rotation of the earth on great atmospheric currents, he continues as follows : “ Let us consider the case of two winds, a polar and an equatorial, moving side by side in opposite directions, the polar being to the west of the other. Clearly the two will have a tendency to recede from each other, and in consequence there will be rarefaction at their neighboring borders, producing a reaction in the two currents exactly counterbalancing the force due to rotation. Thus pressure diminishes from their outer toward their, inner or neighboring borders, where there must be a valley or depression of their surfaces. Since the magnitude of this valley depends upon the velocity of the winds, any slackening of velocity in one of them must allow it to break into the other by gravitation and originate a hurricane revolving against the sun. It is the denser polar wind which generally breaks into the equatorial from a northwest direction. Condensation of vapor follows, and then under certain conditions a hurricane. Now to take the other case—what will happen if the polar current flows on the east of the equatorial? The effect of the rotation of the earth will be a heaping up or condensation of air at their neighboring borders, and the heavier current as before will invade the lighter from southeast, bringing rain. Here, however, there can be no hurricane, for gravitation acts dispersively, and the adjustment of level proceeds outward" instead of inward. If it were possible for a hurricane to arise on the east side of the equatorial current it would rotate 4 with the sun.’ The reason why all hurricanes rotate against the sun is now obvious.” With these principles in mind Mr. Colding thus illustrates the law of Dove: 44 Let us imagine ourselves advancing in a westward direction out of a polar into an equatorial current. The wind turns gradually to east, then it changes to south and southwest as we enter the warm current; then we have it west, northwest, north and finally north-" east, in the polar current on the other side. Now at most stations where observations have been made this direction of shift is the common one. Hence we are led to suppose that the atmosphere as a whole moves sometimes from east to west, but more commonly from west to east. There is good reason for this view. If. the atmosphere consisted of air only there would be no reason for an excess of eastward movement, but the equatorial current, more than the polar, carries a large quantity of vapor, and this causes an excess of pressure from west to east. Therefore,’’concludes the author, 44 Dove’s law is a real law of nature.” From returns made by the General Agent of the National Board of Fire Underwriters it is shown that the losses by fire for the months of May and June last in the United States ana Canada aggregated $16,427,751'. This is exclusive of losses in California. —The Methodist Episcopal Church has over 140 Christian women engaged daily in spreading the Gospel truth m India.