bell was rung, and the servant entered with a teakettle of boiling water.

The large dish was then filled with the cold, and the water-plate with the boiling fluid.

"Let this large dish represent the ocean," said Mr. Seymour," and this water-plate, which I will now place in its centre, an island in that ocean; for the land, from receiving the rays of the sun, will be more heated than the water, and will consequently rarefy the air above it.-Now, Tom, light me the wax taper."

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"I have done so."

"Then now blow it out."

"I cannot imagine what you are about, papa ; Light the candle, and then blow it out!'-but it still smokes, shall I put the extinguisher over it ?"

"By no means; give it to me, and observe what will happen when I carry it round the edge of the dish."

"The smoke goes to the centre," exclaimed Tom.

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Showing, thereby, the existence of a current towards the water-plate, or island; in consequence of the air above it having been heated, and therefore rarefied. This explains in a very satisfactory manner, a fact which may be constantly observed in our own climate, viz. a gentle breeze blowing from the sea to the land in the heat of the day. Upon the same principle it is, that most of the winds in different parts of the globe may be readily accounted for." (36)

"I suppose," said Tom, "that the air must rush with great velocity, in order to produce wind."

"A very general error prevails upon this subject," replied his father; "the rate of motion has been greatly exaggerated. In a brisk gale, even, the wind does not travel with such velocity, but

that it may be easily traced by the eye; and the sailor is able to watch its progress by the ripple which it produces on the sea."

Has, then, the rate of its motion ever been estimated?" asked Louisa.

"When its velocity is about two miles per hour, it is only just perceptible. In a high wind, the air travels thirty or forty miles in the same period. In a storm, its rate has been computed as being from sixty to eighty miles. It has, also, been ascertained, by experiment, that the air, as it rushes from a pair of blacksmith's bellows, has not a velocity above that of five and forty miles in the hour."

"At what rate, should you think the air travelled this morning, when we flew our kite?" enquired Louisa.

"I should think at about five miles an hour, for it was a pleasant but gentle breeze."

A SHORT DISCOURSE. THE SHUTTLECOCK.-THE SOLUTION OF TWO PROBLEMS CONNECTED WITH ITS FLIGHT.THE WINDMILL. THE SMOKE-JACK.-A TOY CONSTRUCTED ON THE SAME PRINCIPLE. THE BOW AND ARRCW.ARCHERY.-THE ARRIVAL OF ISABELLA VILLERS.

MR. TWADDLETON, on his arrival at the lodge, on the following morning, was informed that Miss Villers was expected at Overton in the evening.

"Your account of that young lady," observed the vicar, "has greatly prepossessed me in her favour ; I only hope that she is not too blue."

"I care not how blue the stockings of a lady may be," said Mr. Seymour, "provided her petticoats be long enough to hide them; and from my knowledge of Miss Villers, I can assure you, ex

alted as are her attainments, they are so veiled by feminine delicacy and reserve, that they may insidiously win, but will never extort our homage."

"Ay, ay," exclaimed the vicar; "I perfectly agree with you in your idea of feminine perfection -short tongues, and long petticoats, Mr. Seymour -But where are my little playmates ?"

"I left Tom and Fanny on the terrace, a short time since," replied Mr. Seymour, "very busily engaged in the game of shuttlecock and battledoor."

"The shuttlecock is an ancient sport," observed Mr. Twaddleton. "It is represented in a manuscript as far back as the fourteenth century; and it became a fashionable game amongst grown persons in the reign of James the First."

"It is a very healthy pastime," said Mr. Seymour, "and, in my opinion, is admirably calculated for females; for, it expands the chest, while it creates a graceful pliancy of the limbs."

"I entirely agree with you; it is the only game with which I am acquainted, in which muscular exercise is gained without compromising gracefulness. But see, here come the two young rogues."

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Papa," exclaimed Tom, "I have been considering whether there is any philosophy in the game of shuttlecock."

"There are two circumstances connected with its flight," replied his father, "which certainly will admit of explanation upon scientific principles; and I should much like to hear whether you can apply them for that purpose. The first is its spinning motion in the air; the second, the regularity with which its base of cork always presents itself to the battledoor; so that, after you have struck it, it turns round, and arrives at your sister's battledoor

in a position to be again struck by her, and sent back to you."

"I perfectly understand what you mean; but I really am not able to explain the motions to which you allude," said Tom.

"The revolution of the shuttlecock, about its axis, entirely depends upon the impulse of the wind. on the oblique surfaces of its feathers; so that it is often necessary to trim the feathers of a new shuttlecock, before it will spin."

"I understand you, papa; the force of the wind, by striking the oblique feathers, is resolved into a perpendicular and parallel force, as you explained to us, when we considered the action of the wind upon the kite."

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Exactly; every oblique direction of a motion is the diagonal of a parallelogram, whose perpendicular and parallel directions are the two sides. Having settled this point, let us consider the second; viz. how it happens that the cork of the shuttlecock always presents itself to the battledoor."

“I should think," said Tom, "that the cork points to the battledoor for the same reason that the weathercock always points to the wind."

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Admirably illustrated!" exclaimed his father; "the cork will always go foremost; because the air must exert a greater force over the lighter feathers, and therefore retard their progress. While we are upon this subject, I will introduce to your notice

some contrivances which are indebted to this same principle for their operation. In the first place there is the arrow; can you tell me, Louisa, the use of the feathers which are placed round its extremity ?"

"To make its head proceed foremost in the air, by rendering its other end lighter, and therefore