of wind, rain, snow, and hail. These, though highly important and deserving the attention of the chemist and the student in general philosophy, seem not connected with astronomy; nor deserving a place in a work intended to be exclusively astronomical.

But Aerolithes, or Falling Stones, seem worthy of some notice, even in a compendium of astronomy. It must be reckoned,' says Rees' Cyclopædia, among the wonders of the age in which we live, that considerable portions of these heavenly bodies are now known to have descended to the earth. So wonderful and unexpected an event was at first received (with incredulity and ridicule} but we may now venture to consider the fact, as well established as any other hypothesis. of natural philosophy, which does not actually admit of mathematical demonstration.'

One of the earliest accounts we have of these phenomena is given by Livy, in his History of Rome.) He tells us, that in the time of Tullus Hostilius, the successor of Numa, and third king of Rome, it was announced to the king and to the fathers, that it rained with stones on mount Albanus; that these stones fell from heaven not otherwise than when the winds drive the hail thick to the earth.

Pliny mentions, that a large stone fell in Thrace, in the second year of the 78th Olympiad.

Three large stones are said to have fallen in Thrace, in the year before Christ 452.

It would be useless to dwell on the numerous accounts of these phenomena handed down to us from great antiquity. But it may be proper to give a few instances of the falling of these stones in modern times, received on the authority of different authors.

A shower of falling stones, 1200, one of 120 lbs. is related to have happened near Padua, in Italy, in 1510.

To pass over other numerous and wonderful accounts of these meteors, that of Humboldt, witnessed by himself and Bonplant, in South America, seems too singu

lar not to deserve notice. The night of the 11th of November, 1779, was cool and extremely beautiful. Toward the morning from half after two, the most extraordinary luminous meteors were seen towards the east. Bonplant, who had risen to enjoy the freshness of the air in the gallery, perceived them first. Thousands of bolides, fireballs, and falling stars, succeeded each other during four hours. Their direction was very regular from north to south. They filled a space in the sky extending from the true east 30° towards the north and south; some of them attained a height of 40°; and all exceeded 25° or 30°. There was very little wind, and no trace of clouds to be seen.'

April 5, 1804, a stone of this kind fell near Glasgow, in Scotland. Several gentlemen of the University well ascertained the particulars of this phenomenon.

<But New England affords one of the best authenticated accounts of these wonderful stones.) Professors Silliman and Kingsby, visited and carefully examined every spot where it was ascertained these stones had fallen. The principal fall was within the bounds of Weston, in Connecticut, though the most northerly was in Huntingdon, on the borders of Weston. Something of the original account deserves to be extracted. 'The meteor which has so recently excited alarm in many, and astonishment in all, first made its appearance in Weston, about a quarter or half past six o'clock, on Monday the 14th of December, 1807. The morning was somewhat cloudy, tningled with spots of clear, a space of 15 along the northern horizon perfectly clear; there was little or no light, except from the moon, just setting.

Judge Wheeler was passing through the enclosure adjoining his house, with his face towards the north, and his eyes on the ground, when a sudden flash across the northern sky made him look up; he immediately discovered a globe of fire, passing behind the first cloud, which was very dark, and obscured the meteor.

In this situation its appearance was distinct, like the sun seen through a mist. Its progress was not so rapid as that of common meteors and shooting stars. When it passed the clear sky, it flashed with a vivid light, not so intense as lightning in a thunder storm, but like what is called heat lightning. Its surface was apparently convex. When not too much obscured by clouds, a conical train of paler light attended it waving, and in length about 10 or 12 diameters of the body. In the clear sky there was a brisk scintillation about it, like a firebrand carried against the wind. It disappeared about 15° short of the zenith, and the same number west of the meridian. It did not vanish instantaneously, but grew fainter, as a red-hot cannon ball would do, cooling in the dark, only much more rapidly.

About 30 or 40 seconds after this, three loud and distinct reports, like those of a four-pounder, near at hand, were heard. They succeeded each other rapidly, and did not occupy above three seconds. Then followed a continual rumbling, like a cannon-ball rolling over a floor, sometimes louder and sometimes fainter.')

There were six places where stones fell on this occasion; the most remote, nine or ten miles from each other. One fell on a rock of granite with a loud report. It was broken into fragments, thrown to the distance of 30 feet, some part reduced to powder. One mass of this fall was found sunk two feet below the surface of the ground. Of the masses found, two weighed 35lb. each, one, 25lb. From the fragments found of one, it was thought, it must have weighed nearly 200lbs.

A great similarity is found in these stones, when examined chemically, in different parts of the world, where they had fallen. But they are very different from the other stones on the surface of the earth.

Much speculation has been excited respecting the origin of the Aerolithes. Prior tells us, The most

prevalent opinion among modern philosophers is, that they are concretions actually formed in the atmosphere itself.' But, that such solid and weighty bodies should be formed in the rare medium of the atmosphere, would be more wonderful than the falling stones themselves. Some have supposed they originate in the asteroids.

Perhaps the most probable opinion is that of La Place, that the stones are projected by lunar volcanoes within the sphere of terrestrial attraction.' The moon is but 240,000 miles from the earth. The force of attraction in different bodies is as the quantity of matter. Of this, that of the earth is to that of the moon, as 1 to .025. Hence the neutral ground between the two bodies must be vastly nearer the moon than the earth. Whenever matter thrown up by a volcano from the moon, passes this ground, it must irresistibly be drawn to the earth.

Is it a fact, that stones have fallen from the visible heavens to the earth? How was the event of their falling first received? Where do we find the earliest account of these falling stones? Has there been many accounts of these stones handed down to us from antiquity? Can you name some instances of these stones falling in modern times? Has New England afforded any well authenticated account of these wonderful phenomena? Can you give some account of the meteor which appeared in Connecticut in 1807, and of the stones which fell on that occasion? What are some of the opinions respecting the origin of falling stones? What appears to be the most plausible opinion?

CHAPTER XVII.

Artificial Globes.

ARTIFICIAL globes, are spheres intended to represent the earth and the visible heavens. They are of two kinds, terrestrial and celestial. On the terrestrial is

represented the earth's surface, diversified with the principal divisions of land and water, forming a spherical map of the whole; on the celestial, the visible heavens distinguished into constellations. For convenient use, a globe of either kind is placed upon a frame. On each, the great imaginary circles of the sphere, the tropics, and the polar circles, are represented.

The equator on a terrestrial globe is about one-eighth of an inch broad, graduated for longitude 180° each way from the first meridian.

The ecliptic about the same breadth, inclined to the equator in an angle of 23° 28', is divided into signs, and subdivided into degrees, commencing at the first of Aries.

The brazen meridian is a circle of brass encompassing the globe from north to south, crossing the equator at right angles. The upper semicircle of this is graduated, beginning at the equator, and ending with 90° at the poles. The graduation of the lower semicircle begins at the poles, and ends with 90° at the equator. Besides this, there are other meridians drawn on the globe with dark lines, meeting at the poles. 12 of these, 24 semicircles, form the hour lines. The meridian passing through the equinoctial points is the equinoctial colure. Another passing through the solstitial points, is the solstitial colure. The horizon is represented by a broad circle of wood, divided into four points, east, west, north, south, called the cardinal points. Next to the globe on this, are the amplitudes, graduated into four nineties, commencing at the east and west points. Without these are the azimuths, graduated into four nineties, beginning at the poles. Next to these, are the 32 points of the compass, containing 11° 15' each. Beyond these are the 12 signs, having the appropriate name, figure, and character; each sign graduated as in the ecliptic.

On the exterior circle of the horizon are represented the days of the months, adjusted to the signs, so that