MONSOON, in physiology, a species of trade wind, in the East Indies, which for six months blows constantly the same way, and the contrary way the other six months. However, it ought to be ob served, that the points of the compass from whence the monsoons blow, as well as the times of their shifting, differ in different parts of the Indian ocean.
The cause of monsoons is this : when the sun approaches the northern tropic, there are countries, as Arabia, Persia, India, &c. which become hotter, and re. flect more heat than the seas beyond the equator, which the sun has left; the winds, therefore, instead of blowing from thence to the parts under the equator, blow the contrary way ; and, when the sun leaves those countries, and draws near the other tropic, the winds turn about, and blow on the opposite point of the compass. See WIND.
MONTGOLFIEIt (SrarIZN JANIS), in biography, famous as the inventor of aerostatic balloons, was born at Annonay, thirty-six miles from Lyons, and there carried on an extensive manufacture of paper, in conjunction with his brother Joseph. They were distinguished for their ingenuity in this branch, and were the first in France who made the beauti. ful vellum paper. It is said, that the in cident of covering a coffee-pot, in which water was boiling, with a spherical cap of paper, which rose in the air as the water heated, first gave him the idea of an air balloon. Others affirm, that re flecting on the ascent of smoke and clouds in the atmosphere suggested the hint. However this were, it appears that Stephen, in the middle ofNovember,1782, made an experiment at Avignon with a bag of fine silk, of the shape of a paral lelopipedon, and of forty cubic feet in capacity, to the aperture of which he ap- ' plied burning paper till it was filled with a kind of cloud, when it ascended rapidly to the ceiling. This experiment was re peated by the two brothers at Annonay, with a success that induced them to form a machine of the capacity of six hundred and fifty cubic feet, which, filled in like manner with smoke, ascended to the height of six hundred feet. They proceeded enlarging the experiment, till they had constructed a globe of linen, lined with paper, of the capacity of twenty-three thousand four hundred and thirty cubic feet,.which, inflated with the smoke of straw and chopped wool, rose to an elevation of about six thousand feet.
This power of ascent M. Montgolfier at tributed not merely to the rarefaction of the air from the heat (which appears to be the true cause), but to a species of gas specifically lighter than common air, supposed to be disengaged from the burn ing substances. When the event of these experiments was reported at Paris, the philosophers of that capital immediately thought of applying, for the purpose of inflation, a gas which they knew to be eight or ten times lighter than common air, namely, inflammable air, and trials were immediately made upon that prin ciple, which have proved highly success ful. In the mean time, Montgolfier con tinued to extend his plans, and on Sep tember 19, 1783, he exhibited before the king and royal family, at Versailles, a grand machine, near sixty feet high, and forty-three in diameter, which ascended with a cage, containing a sheep, a cock, and a duck, and conveyed them through the air in safety to the distance of above ten thousand feet. Emboldened by this success, M. Pilatre de Rozier first offered himself to undertake the hazardous ad venture of an aerial navigation, in a new machine of Montgolfier's of still larger dimensions. After first ascending alqne to the height of eighty-four feet, he again seated himself in the car with the Mar quis d'Arlandcs, when they gave all Park the astonishing spectacle of hovering in the air over that city for about nine mi nutes, at the height of three hundred and thirty feet. This brilliant experiment caused the annual prize of the Academy of Sciences to be awarded to M. Mont golfier, and from that sera, October 19, 1783, the atmosphere has been a new field of human daring. The first principle of ascent, however, though applied in va rious succeeding instances, gradually gave way to the safer and more effica cious one of a gaseous fluid permanently lighter than the air. In one unfortunate instance the two modes were combined, and the result was, that the balloon caught fire, and occasioned the death of the first adventurer, Pilatre de Roziert, and his companion Romain. Montgolfier was rewarded for his discovery by admis sion into the Academy of Sciences, the cordon of St. Michael, and a pension of two thousand livres. He died in 1799.