[ 19, 3 may be another caufe of our general north-weft winds, which blow otr to fea at right angles front our North American coati r the warm light fea air riling, the heavy cold land air prof-ling into its pbHce.
eavy fluids denending frequently form eddies, or whirlpools, as is ken in a funnel, where the water acquires circular motion receding every way front a centre, and leaving a vacancy in the middle, greaten
above, and leffcning downwards, like a fpeaking trumpet, its big end upwards. Air dcfcending, or attending, may form the fame kind of eddies, or whirlings, the parts of air ac-
quiring a circular motion, and receding from the middle of the circle by a centrifugal force, and leaving there a vacancy, if deli:ending, greaten above, and terming downwards r if afcending, greaten below, and len:ening ripwards, like a fpeaking trumpet, flanding its big end on tire ground.
When the air defcends with violence in fome it may rife with equal violence n others,
and form both kinds of whirlwinds. Thc air in its whirling motion receding every way from the centre, or .15, of the trumpet, leaves there a vacuum, which cannot be filled through the tides, the whirling air as an arch preventing it mull then prefs in at the open ends.
The greaten prcfinre inwards mull be at the lorver
end, the greaten weight of the furrounding atmofphere being there. The air entering riles within, and carries up duff, leaves, and even heavier bodies that happen in its way, as the eddy or whirlpool panes over land.
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