Democratic Sentinel, Volume 4, Number 50, Rensselaer, Jasper County, 21 January 1881 — The Trade Winds. [ARTICLE]

The Trade Winds.

The earth turns on its axis from west to east, and with it rotates daily the envelope of the atmosphere. The velocity of rotation at the equator is something over 1,000 miles an hour; at thirty degrees distance it is about 150 miles less. In higher latitudes it is still less, at the poles nothing. Therefore, whenever the air moves north or south on the surface of the earth, it will carry with it less or greater velocity of the rotation than the place it passes over, and will turn in an easterly or westerly wind, according as it approaches or recedes from the equator. In the region of the sun’s greatest heat, the air, rarified, and lighted, is continually rising, and cooler currents come in on both sides to take the place of the ascending volume. As these side currents come from a distance of about thirty degrees from the equator, they have at a starting, an eastward velocity of many miles an hour less than the localities they will eventually reach. Consequently they will appear to lag behind in all tlw course of their progress to the equator—that is. they will have a westerly motion united with their north and south movements. These are the great trade winds, blowing constantly from the northeast on this side, and the southwest on tho other side of the equator.—London Truth.