borders of Point-Lake, in latitude 6540. They flew in circles, uttering loud and harsh screams, and alternately stooping with such velocity, that their motion through the air produced a loud rushing noise: they struck their claws within an inch or two of my head. I endeavoured, by keeping the barrel of my gun close to my cheek, and suddenly elevating its muzzle when they were in the act of striking, to ascertain whether they had the power of instantaneously changing the direction of their rapid course, and found that they invariably rose above the obstacle with the quickness of thought, showing equal acuteness of vision and power of motion. Although their flight was much more rapid, they bore considerable resemblance to the snowy owl."

THE PEREGRINE-FALCON.

THE great docility of the peregrine-falcon, and the comparative ease with which the birds are procured, has rendered them the most frequent objects of the falconer's care and tuition; and it is this species which is the most commonly used at the present day by those who still occasionally pursue the amusement of hawking. Formerly this sporting diversion was the pride of the rich, and these birds, as well as their eggs, were preserved by various legislative enactments. So valuable were they considered when possessed of the various qualities most in request, that in the reign of James I., Sir Thomas Monson is said to have given £1000 for a cast (a couple) of hawks.

Sir John Sebright, in his Observations on Hawking, before quoted, thus describes the mode of flying peregrinefalcons at herons, as practised in Norfolk :-"A wellstocked heronry in an open country is necessary for this sport; and this may be seen in the greatest perfection at Didlington in Norfolk, the seat of Colonel Wilson. This heronry is situated on a river, with an open country on every side of it. The herons go out in the morning to rivers and ponds at a very considerable distance in search of food, and return to the heronry towards the evening.

It is at this time that the falconers place themselves in

the open country, down-wind of the heronry; so that when the herons are intercepted on their return home, they are obliged to fly against the wind to gain their place of retreat. When the heron passes, a cast (couple) of hawks is let go. The heron disgorges his food when he finds that he is pursued, and endeavours to keep above the hawks by rising in the air; the hawks fly in a spiral direction to get above the heron, and thus the three birds frequently appear to be flying in different directions. The first hawk makes his stoop as soon as he gets above the heron, who evades it by a shift, and thus gives the second hawk time to get up, and to stoop in his turn. In what is deemed a good flight, this is frequently repeated, and the three birds often mount to a great height in the air. When one of the hawks seizes his prey, the other soon binds to him, as it is termed, and, buoyant from the motion of their wings, the three descend together to the ground with but little velocity. The falconer must lose no time in getting hold of the heron's neck when he is on the ground, to prevent him from injuring the hawks. It is then, and not when he is in the air, that he will use his beak in his defence. Hawks have, indeed, sometimes, but very rarely, been hurt by striking against the heron's beak when stooping; but this has been purely by accident, and not, as has been said, by the heron's presenting his beak to his pursuer as a means of defence. When the heron flies down-wind, he is seldom taken; the hawks are in great danger of being lost, and as the flight is in a straight line, it affords but little sport."

THE KESTREL.

THE kestrel is one of the most common species of the British falconida; and from its peculiar habits, which place it very often in view, it is also, as might be expected, one of the best known. It is handsome in shape, attractive in colour, and graceful in its motions in the air; though, from its mode of searching for its food, and the shortness of its wings compared with others of the small raptorial species already figured, it departs from the characters of the true falcons. It is best known, and that too at any moderate

distance, by its habit of sustaining itself in the air in the same place by means of a short but rapid motion of the wings, while its powerful eyes search the surface beneath for mice of different species, which form by far the most considerable part of its food. It has acquired the name of windhover from this habit of remaining with outspread tail suspended in the air, the head on these occasions always pointing to windward.

THE KITE.

THE kite is readily distinguished among the British falconidae, even when at a distance on the wing, by its long and forked tail. The flight of this large bird is singularly graceful and easy, gliding smoothly along with little muscular exertion. It still retains in some districts the name of gled, or glead ; derived, according to Pennant, from the Saxon glida. Occasionally it sails in circles, with its rudder-like tail by its inclination governing the curve; then stops, and remains stationary for a time, the tail expanded widely, and with its long wings sustaining its light body, apparently from the extent of surface the bird is able to cover. In its mode of taking its prey, the kite is distinguished from falcons and hawks generally, by pouncing upon it upon the ground. The nature of the food also makes this habit evident: twenty-two moles were found in the nest of a kite, besides frogs and unfledged birds; it preys also on leverets, rabbits, snakes, and particularly on the young of various gallinaceous birds, before they have acquired the power of using their wings. The kite, like the sparrow-hawk, frequently visits the poultry-yard, but is not remarkable for its courage: hens have been known by their vociferations and their show of resistance to protect their chickens from the threatened attack, and even to drive away the unwelcome intruder.— Yarrell's "British Birds."

GENERAL RELATIONS OF LIGHT, HEAT, ELECTRICITY, AND MAGNETISM.

LIGHT and heat are among the most interesting subjects of human knowledge. Light is the means by which the

whole visible creation is revealed to us; and there is no operation either natural or artificial, in the performing of which heat is not in some way concerned.

A knowledge of the most ordinary properties of heat is so important for every one who wishes to understand science in such a way as that it may be useful, that an instance or two may be mentioned. Common fire is a principle with the action of which everybody is familiar; and whatever may be the fuel with which it is fed, whether common pit-coal, or wood, or turf, or anything else, we always consider the fire, that which burns the fuel, as being the same. We do so, without any regard to the means by which it may be at first kindled. We may obtain it by a brand from a fire already kindled; by striking a piece of steel rapidly with a piece of flint, and catching the sparks on dry tinder; by hammering iron on an anvil; by rubbing one piece of dry wood against another; and by various other means: and a fire may be kindled naturally by lightning, and by various actions of moist bodies,—such as wet hay or other vegetables, and sulphur and iron filings moistened and covered up from the air; and also by the friction or rubbing of very dry bodies against each other, in which way the dry reeds and forests of tropical countries are said to be often set in a blaze.

But in what way soever we obtain it, we always consider it as being the very same fire: and we are right in so doing, and should be wrong if we did otherwise; for whatever may be its source, the same degree of it always produces similar effects on the same substance, if that substance is in the same state, and the fire applied to it in the same

manner.

But this fire, which we must regard as being the same in all cases, as it has the qualities by which alone we can judge of sameness in any thing, acts differently on different substances. Put a piece of pure clay in the fire, and it will remain unaltered, except in size. Sprinkle water on the fire, and it will rise up in steam with a hissing noise; or, if the quantity be great enough, it will carry up all the fire with it, and the fuel will be extinguished. A

piece of fat will soften and melt, but an egg will become hard, though in the end both will be burnt. The same fire, too, which roasts an apple till it is soft and moist, roasts a potato till it is dry and mealy. In all these and in many thousands of other instances that could be given, the difference of effect is in the substance, and not in the principle; and therefore, in order that the science or knowledge of any event that happens, be it what it may, may be useful, we must know the object acted upon, as well as the agent that acts upon it.

Electricity is abundantly diffused throughout nature; its effects are exhibited in a variety of ways, and its influence is probably as essential to the constitution of matter as that of light and heat. Until within the last few years, electrical phenomena were but partially observed, and imperfectly understood. Our knowledge of this important branch of science is now greatly extended, and it is rapidly advancing; that which was once a subject of conjecture, or of vague speculation, being now verified by the most satisfactory experiments. We here allude to the identity of the principle of electricity, whatever may be the difference in its action; for it is perfectly consistent with our experience that the results of the same principle, acting in different ways, and on dissimilar substances, may be just as distinct as if there was a difference in the principles themselves. In treating of electricity, therefore, as a science, it is necessary to divide it into several distinct branches. Thus we have Common, or Ordinary Electricity, which is produced by friction; Voltaic Electricity, called also galvanism, which is the result of chemical action; MagnetoElectricity, or that produced by magnets; and ThermoElectricity, which is developed by heat.

In proportion as facts, illustrative of electrical phenomena, have been multiplied, so have our views expanded respecting magnetism, in which almost everything that was known about twenty years ago, was the power possessed by an ore of iron to communicate permanent polarity, and an attractive and repulsive influence, to iron and steel bars. This property of the loadstone was known to the