Page:Collier's New Encyclopedia v. 01.djvu/66

ÆNEID ÆNEID, one of the great epic poems of the world. It was written in Latin by Vergil, and published after his death, which took place about 16 B. C. Its hero is Æneas, one of the Trojan chiefs, whose adventures during and after the siege of Troy it recounts, till the time when he succeeded in fully establishing himself in Italy.

ÆOLIAN or ÆLIC, one of the three great dialects of the Greek language, the others being the Doric and the Ionic. The expression, Attic dialect, often occurs, but this should be regarded as the normal type of Greek rather than as a divergent dialect of that tongue.

ÆOLIAN HARP, a harp played by Æolus—in other words, by the wind. It is made by stretching strings of catgut over a wooden sound-box. If exposed to the action of the wind, a succession of pleasing sounds proceeds from it, plaintive when the breeze is slight, but bolder as it increases in force.

ÆOLIANS, the name of one of those peoples classed under the general appellation of Greeks. We trace the name of Æolians to Thessaly, their primitive abode, as far as we know, where they appear to have been closely related to the Phthiotic Achæans of the same country. The Æolian colonies on the Asiatic main land were widely spread, extending at least from Cyzicus, along the shores of the Hellespont and the Ægean, to the river Caicus, and even the Hermus. There were 12 cities or states included in the older settlements in that tract of Asia Minor on the Ægean, which was known in Greek geography by the name of Æolis, and formed a part of the subsequent larger division of Mysia. Smyrna, one of them, which early fell into the hands of the lonians, the neighbors of the Æolians, still exists nearly on the old spot, with exactly the same name.

ÆOLUS (ē´ō-lus), the god of the winds, who was fabled by the early poets to have his seat in the floating island of Æolia; but the Latin and later Greek poets placed him in the Lipari Isles. Here the winds were pent up in vast caves, it being the duty of Æolus to let them loose and to restrain their violence at the pleasure of Jupiter.

ÆON, a period of time, a lifetime, a generation; a long space of time, eternity; a space of time clearly marked out; a period, an age, a dispensation.

In modern science and literature, a period of immense duration, specially one of those which geology makes known as the Silurian and Devonian æons.

AËRIAL LAW. See ERONAUTICS.

AËRODYNAMICS, the science which treats of the force exerted by air when in motion.

AËROLITE or AËROLITH, a stone which falls from the air, or sky. The name is somewhat inappropriate, now that it is known that the connection of these stones with the air is but slight, they simply traversing it as, under the operation of gravity, they fall from the regions beyond to the earth. See METEORITE.

AERONAUTICS, the science of artificial flying.

The first ventures into this field date back to 1783. They were based chiefly upon the discovery by Cavendish of hydrogen gas, and his demonstration that it was lighter than air. Scientists were quick to grasp the idea that if containers of sufficient size and light weight could be secured and filled with hydrogen they would ascend. The first experiments in balloons, however, were carried on without the use of hydrogen gas. Stephen and Joseph Montgolfier, brothers, of Annonay, France, in 1783 made a paper balloon of a capacity of 700 cubic feet, which they filled with heated air from a fire beneath the bag. On June 5, 1783, this pioneer in aerial navigation rose to a height of a thousand feet. A little later, a French scientist, Charles, with Cavendish's discovery in mind, planned a balloon which should be filled with hydrogen gas instead of heated air. The first obstacle encountered was the difficulty of creating a perfectly airtight envelope. This was overcome by the discovery by two brothers named Roberts, that a coating of dissolved rubber over silk fabric would prevent the hydrogen gas from escaping. The test of this new balloon was made on Aug. 20, 1783, and the bag as soon as liberated rose to a great height, but because of too great inflation of the gas split asunder and fell to the ground.

Hitherto the balloons had carried no passengers, but on Nov. 21, 1783, Pilâtre de Rozier and the Marquis d'Arlandes sailed over the Seine and a large part of Paris in a balloon filled with heated rir, remaining above the earth 25 minutes. A few days later, Dec. 1, an ascent was made by Messrs. Charles and Roberts in a balloon filled with hydrogen gas. In the two years ensuing, many flights were made, the most notable of which was that of Blanchard, the Englishman, who, accompanied by an American, Dr.