NOTE XXXIII … WINDS.
Air is perpetually subject to increase and to diminution; Oxygene is perpetually produced from vegetables in the sunshine, and from clouds in the light, and from water; Azote is perpetually produced from animal and vegetable putrefaction, or combustion; from springs of water; volatile alcali; fixed alcali; sea-water; they are both perpetually diminished by their contact with the soil, producing nitre; Oxygene is diminished in the production of all acids; Azote by the growth of animal bodies; charcoal in burning consumes double its weight of pure air; every barrel of red-lead absorbes 2000 cubic feet of vital air; air obtained from variety of substances by Dr. Priestley; Officina aeris in the polar circle, and at the Line. South-west winds; their westerly direction from the less velocity of the earth's surface; the contrary in respect to north-east winds; South-west winds consist of regions of air from the south; and north-east winds of regions of air from the north; when the south-west prevails for weeks and the barometer sinks to 28, what becomes of above one fifteenth part of the atmosphere; 1. It is not carried back by superior currents; 2. Not from its loss of moisture; 3. Not carried over the pole; 4. Not owing to atmospheric tides or mountains; 5. It is absorbed at the polar circle; hence south-west winds and rain; south-west sometimes cold. North-east winds consist of air from the north; cold by the evaporation of ice; are dry winds; 1. Not supplied by superior current; 2. The whole atmosphere increased in quantity by air set at liberty from its combinations in the polar circles. South-east winds consist of north winds driven back. North- west winds consist of south-west winds driven back; north-west winds of America bring frost; owing to a vertical spiral eddy of air between the eastern coast and the Apalachian mountains; hence the greater cold of North America. Trade-winds; air over the Line always hotter than at the tropics; trade-winds gain their easterly direction from the greater velocity of the earth's surface at the line; not supplied by superior currents; supplied by decomposed water in the sun's great light; 1. Because there are no constant rains in the tract of the trade-winds; 2. Because there is no condensible vapour above three or four miles high at the line. Monsoons and tornadoes; some places at the tropic become warmer when the sun is vertical than at the line; hence the air ascends, supplied on one side by the north-east winds, and on the other by the south-west; whence an ascending eddy or tornado, raising water from the sea, or sand from the desert, and incessant rains; air diminished to the northward produces south-west winds; tornadoes from heavier air above sinking through lighter air below, which rises through a perforation; hence trees are thrown down in a narrow line of twenty or forty yards broad, the sea rises like a cone, with great rain and lightning. Land and sea breezes; sea less heated than land; tropical islands more heated in the day than the sea, and are cooled more in the night. Conclusion; irregular winds from other causes; only two original winds north and south; different sounds of north-east and south-west winds; a Bear or Dragon in the arctic circle that swallows at times and disembogues again above one fifteenth part of the atmosphere; wind- instruments; recapitulation.