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Th; Sun, that amazing Globe of Fire, the Fountain of Light and Heat of the whole solar System, whose Rays upon the Earth cause Vapours or Fumes to be continually rising from it, which must partake of the Quality of those Parts from whence they are evaporated; a Collection of which form what we call our Air or Atmosphere, surrounding the Earth, and extending some Miles above its Surface, and is liable to be put in Motion by various Causes, Hence Air is a fine elastic Fluid, and is found capable of being compressed, or condensed by Cold, and expanded or rarefied by Heat. Consequently, an Alteration of Heat or Cold happening in any . Part of the Atmosphere, the Air in that Part will be either condenscd or rarified, and the neighbouring Parts will thereby be put into, Motion, through the Endeavour which the Air by its Elasticity or Springiness always makes to restore itself to its former State, or, come to an Equilibrium, Wind is arStream or Current of Air, which generally blows from one Part of the Horizon to its opposite Part. The following Observations have been made on it, particularly by Dr. Halley, which are not unworthy the Seaman's Notice. Between 30 Degrees North Latitude, and 30 South Latitude, there is a constant East Wind throughout the Year, blowing on

the Atlantic and Pacific Oceans, and this is called the Trade

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... must be had to the Nature of Soils, and the Position of high Moun

tains, which are the principal Causes of the Variety of Winds difering from the former general one. - o R 2 In

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out of the Trade Winds, immediately find a Wind blowing from the

opposite Quarter. In the Atlantic Ocean, near the Coasts of Africa, at about 100 Leagues from Shore between the Latitudes of 28° and 10° North, Seamen constantly meet with a fresh Gale of Wind blowing from the N. E. Those bound to the Caribbee Islands across the Atlantic, find, as they approach the American Side, that the said N. E. Wind becomes. Easterly, or seldom blows more than a Point from the East either to: the Northward or Southward. * These Trade Winds on the American Side are extended to 30°, 31°, or even to 32° of North Latitude ; which is about 4° farther than what they extend to on the African Side; also to the Southward of the Equator, the Trade Winds extend 3 or 4 Degrees farther towards the Coast of Brazil on the American Side, than they do near the Cape of Good Hope on the African Side. Between the Latitudes of 4 Degrees North, and 4 South, the Wind always blows between the South and East: On the African Side the Winds are nearest the South, and on the Amcrican Side nearest the East. In these Seas Dr. Halley observed, that when the Wind was Eastward, the Weather was gloomy, dark, and rainy, with hard Gales of Wind ; but when the Wind veered to the Southward, the Weather generally became serene, with gentle Breezes next to a Calom; These Winds are somewhat changed by the Seasons of the Year; for when the Sun is far Northward, the Brazil S. E. Wind gets to the South, and the N. E. Wind to the Fast ; and when the Sun is far South. the S. E. Wind gets to the East, and the N. E. Wind on this Side of the Equator veers more to the North. Along the ğ. Guinea, from Sierra Leona to the Island of St. Thomas under the Equator, which is above 5co Leagues, the Southerly and South-west Winds blow perpetually; for the S. E. Trade Wind having passed the Equator, and approaching the Guinea Coast, within 80 or roo Legues, inclines towards the Shore, and becomes S. S. E., then South, and by Degrees, as it comes near the Land, it veers about to S. S. W. and in with the Land it is S. W. and sometimes W. S. W. This Track is troubled with frequent Calms,

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All Navigation in the Indian Ocean must necessarily be regulated by these Winds; for if Mariners should delay their Voyages till the contrary Monsoon begins, they must either sail back, or go into Harbour, and wait for the changing of the Trade Winds.

Vapours rising from the Sea, and by the Wind carried over low Lands to the Ridges of Mountains, and compelled to mount up with the Stream of the Air to the Tops, where the Water presently precipitates gleeting down by the Chinks and Cliffs of the Stones, and Part of the Water entering into the Caverns of Hills, and gathering into Basons, which being once filled begin to run over, and form subterraneous Passages through the Earth, breaking out in Springs by the Sides of Hills; several of those meeting together form Rivulets; several of these Rivulets meeting together make a River. This, together with what is incorporated into Vegetables, renders it impossi

ble for all the Water evaporated from the Sea to return to it again. Hence the Evaporations arising from the Mediterranean are such, that notwithstanding there are 9 capital Rivers, which empty themselves into it, besides smaller ones, there is a constant Current running through the Straits of Gibraltar from the Atlantic Ocean, to make up the Deficiency. R. Mead, M. D. and F. R. S. observes, 1. That some Diseases are properly the Effects of the Influence of the heavenly Bodies. 2. That the most windy Seasons of the Year are - about the vernal and autumnal Equinoxes. 3. All the Changes we have enumerated in the Atmosphere do fall out at the same Times when those happen in the Ocean, and, as both the Waters of the Sea and the Air of our Earth or Fluids, are subject in a great Measure to the same Laws of Motion, so that natural Effects of the same Kind are owing to the same Causes. 4. The Alteration made by the Sun and Moon in the Atmosphere must thereby have Influence on the Animal Body. 5. The Elasticity of the Air is of great Moment, and it is reciprocally as the Pressure, so that the incumbent Weight be2ng diminished by the Attraction, the Air underneath will be much expanded; these, and such like Causes, will make the Tides in the Air to be much greater than those of the Oceañ; and there is no doubt to be made, but that the same infinite wise Being, who contrived the Flux and Reflux of the Seas, to secure that vast Collection of Waters from Stagnation and Corruption, has ordered this Ebb and Flood of the Air of our Atmosphere with the like good Design; that is, to preserve it sweet, and a brisk Temper of this Fluid so necessary to Life, by a continual Circulation. 6. Two contrary Winds blowing towards the same Place, may accumulate the Air there, so as to increase the Height and the Weight of the incumbent Cylinder; in like Manner the Direction of two Winds may be such, as meeting at certain Angles, may keep the Gravity of the Airin a middle State ; but if the Winds blow different Ways from the same Place (which may be occasioned by Thunder and Lightning) the Height and Veight of the Air may be much decreased. 7. The Changes in our Atmosphere at High Water, New and Full Moon, the Equinoxes, &c. must occasion Alterations in all Animal Bedics, for all living - Creatures

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