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shining vapour, and to roll from the south to the north. In about half an hour, its course was changed; it then became vertical, and about nine o'clock it extended across the heavens from N. E. to S. W.; at intervals, the continuity of the luminous arch was broken, and there then darted from its south-west quarter, towards the zenith, strong flashes and streaks of bright red, similar to what appears in the atmosphere during a great fire in any part of the metropolis. For several hours the atmosphere was as light in the south-west as if the sun had set but half an hour ; and the light in the north resembled the strong twilight which marks that part of the horizon at Midsummer. Thomson, speaking of the aurora borealis, and other meteors, says

-Silent from the north,
A blaze of meteors shoots ; ensweeping first
The lower skies, they all at once converge
High to the crown of heaven, and all at once

Relapsing quick, as quickly re-ascend,
And mix and thwart, extinguish and renew,
All æther coursing in a maze of light.

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James. How do you account, sir, for the Will-with-the-wisp, or Jack-a-lanthorn, that is close to the ground where the air is thickest ?

Tutor. This is a meteor which seldom appears more than six feet above the ground; it is always about bogs and swampy places, and these, in hot weather, emit what is called inflammable air, which is easily inflamed by the electric spark. These, therefore, as you shall see in our chemical experiments, we can as readily imitate as the aurora borealis.In some parts of Italy, meteors of this kind are frequently very large, and give a light equal to that of a torch.

Water-spouts, which are sometimes seen at sea, are supposed to arise from the power of electricity.

Charles. I have heard of these, but ! thought that water-spouts at sea, and whirl. winds and hurricanes by land, were produced solely by the force of the wind.

Tutor. The wind is, undoubtedly, one of the causes, but it will not account for every appearance connected with them. Water-spouts are often seen in calm weather, when the sea seems to boil, and send up a smoke under them, rising in a sort of hill towards the spout. A rumbling noise is often heard at the time of their appearance, which happens generally in those months that are peculiarly subject to thunder-storms, and they are commonly accompanied or followed by lightning. When these approach a ship, the sailors present and brandish their swords to disperse them, which seems to favour the conclusion, that they are electrical.

James. Do the swords act'as conduc

tors ?

Tutor. They may, certainly ; and it is known that by these pointed instruments they have been effectually dispersed.

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The analogy between the phenomena of water-spouts, and electricity, may be made visible by hanging a drop of water to a wire, communicating with the prime conductor, and placing a vessel of water under it. In these circumstances, the drop assumes all the various

appearances

of ter-spout, in its rise, form, and mode of disappearing

Water-spouts, at sea, are undoubtedly very like whirlwinds and hurricanes by land. These sometimes tear up trees, throw down buildings, make caverns; and, in all the cases, they scatter the earth, bricks, stones, timber, &c. to a great distance in every direction. Dr. Franklin, mentions a remarkable appearance which occurred to Mr. Wilke, a consdierable electrician. On the 20th of July, 1758, at three o'clock in the afternoon, he observed a great quantity of dust rising from the ground, and covering a field, and part of the town in which he then was. There was no wind, and the dust moved gently

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Charles. I have heard of these, but I thought that water-spouts at sea, and whirlwinds and hurricanes by land, were produced solely by the force of the wind.

Tutor. The wind is, undoubtedly, one of the causes, but it will not account for every appearance connected with them. Water-spouts are often seen in calm weather, when the sea seems to boil, and send up a smoke under them, rising in a sort of hill towards the spout. A rumbling noise is often heard at the time of their appear. ance, which happens generally in those months that are peculiarly subject to thunder-storms, and they are commonly ac. companied or followed by lightning. When these approach a ship, the sailors present and brandish their swords to disperse them, which seems to favour the conclusion, that they are electrical.

James. Do the swords act'as conductors ?

Tutor. They may, certainly ; and it is known that by these pointed instruments they have been effectually dispersed.

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