19, 1752, and appeared in the Gentleman's Magazine.

"Make a small cross of two light slips of "cedar, the arms so long as to reach to the four . corners of a large silk handkerchief when ex"tended; tie the corners of the handkerchief to "the extremity of the cross; so you have the "body of a kite; which being properly accom

modated with a tail, loop, and string, will rise "in the air like those made of paper, but being "of silk is fitter to bear the wet and wind of a "thunder gust without tearing. To the top of "the upright stick of the cross is to be fixed a ་ very sharp pointed wire, rising a foot or more "above the wood. To the end of the twine "next the hand, is to be tied a silk ribbon, and "where the silk and twine join a key may be "fastened. This kite is to be raised when a "thunder gust appears to be coming on, and "the person who holds the string must stand "within a door or window, or under some cover,

SO that the ribbon may not be wet: and care must be taken that the twine does not touch "the frame of the door or window. As soon as any of the thunder clouds come over the "kite, the pointed wire will draw the electric "fire from them, and the kite with all the twine "will be electrified, and the loose filaments of "the twine will stand out every way, and be "attracted by an approaching finger. And when "the rain has wet the kite and twine, so that "it can conduct the electric fire freely, you wilk "find it stream out plentifully from the key on "the approach of your knuckle. At this key "the phial may be charged, and from electric "fire thus obtained, ardent spirits may be

"kindled, and all other electrical experiments "be performed which are usually done by the "help of a rubbed glass globe or tube, and "thereby the sameness of the electric matter "with that of lightning completely demon"strated. "B. F."

2. But how is this applied to the protection of houses?

A. This Dr. Franklin had also the glory to invent. "In September, 1752, he erected an iron rod to draw the lightning down into his house, in order to make some experiments, in which he succeeded; he discovered the two kinds of electricity, and that the force of thunder very often proceeds from the earth to the clouds, as well as from the clouds to the earth; that the cause of thunder and lightning is by the collision of two bodies, one positively and the other negatively charged....or with too much in one and too little in the other; that the effort to become equal causes the thunder; and the stream of lightning is the same as the electric spark; metal conductors therefore carry on the communication between the clouds and the earth, and prevent the consequences that otherwise would result."

THE AURORA BOREALIS.

Q. What is the cause of the Aurora Borealis, or that shining light which is often seen by night in the heavens, and which the vulgar call northern lights or streamers?

A. Formerly it was believed to be the result of certain nitrous and sulphurous vapors, thinly spread through the atmosphere above the clouds, where they fermented, and taking fire, the explo

sion of one portion kindled the next, and the flashes succeed one another till all the vapour is set on fire, the streams whereof seem to converge towards the zenith of the spectator, or that point of the heavens which is immediately over his head.

2. Whence is its name derived?

A. Its name implies the northern light, because it was first noticed, and for some time supposed to be peculiar to the northern hemisphere; but it has been since discovered in the southern hemisphere also, and there it is called Aurora Australis. It usually appears in the winter, and during frosty weather. It exhibits a roseate or Aurora reddish color, with corruscations that -give a tinge of yellow and of purple; the vibra tions are present and visible by the pale light which they throw forth like the pulmonary throbs of the phospher or fire fly; they appear to rise from the earth in undulations or waves, and move with velocity to the zenith; and a sound is often heard like the rustling of silk garments.

2. When was this meteor first seen?

A. It is believed by many judicious writers, that the ancient traditions and stories of battles in the air, may be resolved by the aurora borealis....which sometimes exhibits an activity of motion, concussion, and repercussion, which conveys an idea not very remote from military action; in some parts of Europe this action has caused them to be called merry dancers.

2. What accounts are there of them more modern?

A. There are accounts of it so early as November 14, 1574; 6th March, 1716, which was

very brilliant; but it does not appear either frequently or at stated periods, or of equal brilliancy. 2. What is its elevation from the earth?

A. That of 1737, was found by Boscovitch to be 825 miles high; and M. Marian determines its mean height at 464 miles.

2. How has it been accounted for latterly? A. The most satisfactory account is allowed to have been given by the venerable Franklin, in 1779, and demonstrates it to be the combined effect of rarefaction and condensation of the air, acted upon in the operation or change by electricity.

2. When was it discovered in the south?

A. By Captain Cook, the celebrated navigator, in 1770, and afterwards in 1773. The Aurora Australis was not tinged with red, but of a clear white, the corruscations of which were a sudden disappearance and reappearance, without the tremulous and vibratory motion which has uniformly appeared on the northern. It is not known to produce any effects on our earth or atmosphere.

AN EPITOME.

OF THE

ARTS AND SCIENCES.

CLASS X....LESSON I.

OF GEOLOGY.

AS in our early lessons we have treated of cosmography, or the system of the universal creation, and of geography, or the general distribution of the surface of the earth, we should now enquire concerning the composition and form and properties of the earth; under what heads shall we do this?

A. As astronomy describes the particulars of the heavenly bodies; and chemistry the properties of natural substances, so we should by geology, study the structure and formation of the globe, the materials of which it is composed, the changes it appears to have undergone; and this branch of science, with chemistry and mineralogy, render our knowlege of the substances of the earth clear and satisfactory; while botany, and the enquiries into animated nature, complete the whole.

2. What is most remarkably deserving of regard in geology?

A. The phenomena which it presents to our senses, the solid masses of which our earth is composed, their variety and the consistency of their distribution, though in apparent disorder.

2. What do you mean by a consistent distribution?