A. Annexed are two drawings which give a very faithful picture of this phenomenon.

Fig. I. aa is a large body of sea water rising in the form of a spiral column into the air. bb The sea agitated around the base of the column.

cc A watery cloud, or mist, elevated to a vast height.

dd The vortex in which it terminates.

ee ff The descending spout from the dark cloud above.

gg The cloud from whence the spout descends by the vertiginous motion of the air, in a

whirl.

Fig. II. Exhibits a spout seen near the island of St. Helena, by which it appears that the neighborhood of land affects the form and course of action of the spout.

Are these all of the same appearance ?

A. The drawings give a very accurate idea of them generally; but some do not appear so beautiful; and many of them to the amount of twenty or thirty at a time are seen in the neighborhood of the equator.

OF THE IRIS, OR RAINBOW, AND HALOS.

2. What is the Iris or Rainbow?

A. A beautiful arch in the heavens, ornamented with various colors, which is seen only when the spectator turns his back to the sun, and when it rains on the opposite side. Its colors are, beginning from the under part, violet, indigo, blue, green, yellow, orange, and red.... These are called the seven primary colors.

What was the opinion of the ancients conthis meteor?

cerning

4. Its beautiful colors struck antiquity with amazement. To the philosophers Pliny and Plutarch, it appeared as an object which we might admire, but could not explain. The priests always preferred the wood on which the rainbow had appeared to rest for their sacrifices; vainly supposing that this wood had a perfume peculiarly agreeable to their deities. Some philosophers of the obscure ages began to form more just conceptions concerning this meteor; but as they were ignorant of the true cause of the colors, they left the task unfinished for the incomparable Newton to complete.

2. Please to explain how the rainbow is produced, and how it acquires its beautiful appearance?

A. It is made, according to his theory, by the rays of the sun being refracted by the drops of rain falling on mist, and thence reflected to the spectator's eye. The rays of the sun falling on the drops of rain, fall on the eye of the spectator, who must be between the sun and the rain in order to see the rainbow; the drops being suc-cessively higher than each other, the rays least refracted produce red, those most refracted produce violet, and the intermediate as in the above order.

2. There are sometimes two rainbows at the same time, how are they accounted for?

A. The interior bow is produced by one reflection of the rays of the light, the exterior and fainter is produced by two reflections, and if you will attend to it you will find that their colors are in a contrary arrangement: an easy experiment proves the cause of the rainbow; provide a transparent glass globe, and fill it with pure

water, hang it in the sunshine and view it in such a position, as that the rays which come from the globe to the eye, may, with the sun's rays, include an angle of about 42 degrees, the spectator will see a full red color in that side of the globe opposite to the sun; and if the angle be made less by depressing the sun or raising the eye, the other colors will appear in succession.

All the colors of the rainbow may be produced by making the rays of the sun pass through a transparent prism of glass.

2. You have said nothing of the rainbows that sometimes appear by night during moonlight ;what think you of them?

A. The lunar rainbow is formed exactly in the same manner, by the bright beams of the moon striking upon the bosom of a shower.

2. How do you account for that lucid ring we see diffused round the moon, called a halo?

A. This appearance is also called the corona, or crown, from its encircling the sun, moon, or other planets; and they sometimes exhibit the prismatic colors, like the rainbow. As this mostly appears in a misty or frosty season, we may suppose it occasioned by the refraction of light on the moist or frozen particles of the air.

CLASS IX....LESSON IX.

OF ELECTRICITY.

Q. WHAT is electricity?

A. The science of electricity is that by which the principles and causes of thunder and lightning are accounted for by mechanical experiment; and by which houses, ships, and other elevated objects, may be protected from the violence of lightning.

As a substance, or principle of nature, subtle and in general invisible, denominated the electric fluid, which appears to pervade all nature, and to enter largely into the elementary causes of vegetable and animal life.

2. Whence is it derived?

A. From electrum, which means amber, a substance the attractive power of which was ob served 603 years before the Christian era.

2. Is electricity then an ancient discovery? A. By no means; mere mechanical electricity or the productions of sparks and attractions by machinery, was known about the beginning of the 17th century, and some publications made on the subject by Dr. William Gilbert; about 1733, Mr. Grey and the abbe Nollet gave some account of experiments of theirs; but the discovery and demonstration belong to America, and to the city of Philadelphia, of the identity of the electric fluid and lightning.

2. Who was the author of this discovery? A. The venerated man, Benjamin Franklin, who by his sagacity and genius reduced the fact to proof by means simple and surprizing.

2. At what period did Dr. Franklin make this discovery?

A. The first accounts of his experiments published, are dated 28th March, 1747, at Philadelphia, from that period his experiments were continued for several years.

2. What is its nature?

A. Electricity is of two kinds, positive and negative; the first is that state of a body when it contains more than the usual proportion distri buted through other parts of the universe; the latter is when a body contains less than the due proportion; and both or either may be produced artificially, as well as naturally.

Q. How does it operate?

A. There are bodies which are called electrics, these are non-conductors, or have the power of stopping the communication between bodies, such as glass, amber, sealing wax, rosin; these are also called electrics, per se, or by themselves.

There are other substances called non-electrics, which though incapable of being excited, can in certain circumstances convey the electric power from one body to another; these also are called conductors, the most perfect of which are water, metals, charcoal. An electric machine being prepared, and a conductor being presented to it, the electric fluid will pass; but if a non-electric, such as glass or rosin, is interposed, none will

pass.

2. The subject is interesting; I wish to be more particularly acquainted with it..

A. The best explanation I can give is in the words of Dr. Franklin himself, which I find in his works, it was written in 1752, wherein he explains the grand experiment by which he drew lightning from the clouds. It is dated October