Barometric Fluctuations
Description
This section is from the book "A Dictionary Of Modern Gardening", by George William Johnson, David Landreth. Also available from Amazon: The Winter Harvest Handbook: Year Round Vegetable Production Using Deep Organic Techniques and Unheated Greenhouses.
Barometric Fluctuations
1. The barometer in calm serene weather generally ranges pretty high, rather above thirty inches; if the fluctuations daily are very small, but still rather getting higher, a fine series of days or weeks may be expected.
2. When the barometer is below twenty-nine inches, and the clouds disperse with but little wind, it will become stationary for a day or two, till the electrical equilibrium of the air be destroyed: if it then rise, expect fair weather; if it fall, expect a storm of wind accompanied with rain or hail, according to the season.
3. When the barometer ranges between 29 and 29.60, if the clouds hang low and float before a west or southwest wind, almost every cloud will deposit its contents, especially if passing over an elevation, a wood, and sometimes a river. In all cases the hygrometer should be considered: if the air be dry and the barometer fall, wind will follow; if the air be saturated with moisture, rain or sleet, according to season.
4. When the thermometer ranges in summer between 70° and 80°, and the barometer falls rapidly and extensively, thunder will follow with hail or heavy rain.
5. In winter, when the thermometer ranges below freezing, and a low barometer begins to rise, expect snow to follow; but if the thermometer rise and the barometer fall during frosty weather, a thaw will quickly follow.
6. The barometer at all seasons of the year will fall very low and very rapidly on the approach of a storm of wind without rain; on the approach of an earthquake too, though it be four or five hundred miles off!
7. If the barometer fall with an easterly or northeast wind, rain will follow.
8. If the crown of the mercury in the tube be convex, it indicates a rising will take place; if concave, it will soon fall.
These are a few of the changes peculiar to England. The operating causes of the oscillations involve one of the most interesting inquiries belonging to meteorology. Electricity is the grand mover of the barometric column. Many other rules might be gathered from the restlessness of animals, the flights of birds, and the gambols of fishes; all indicating by their motions that there is a change taking place in the electrical condition of the atmosphere.
Continue to:
My Books
