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more commonly a storm." But this term is variously applied in different countries. In some instances a violent agitation of the atmosphere is called a storm of wind; and we have, moreover, (( hail-storms," 66 snow-storms," "sand-storms," &c.

It has been explained that there are storms of regular occurrence in many countries situated in the torrid zone, called monsoons, simooms, tornadoes, &c. Of these it is unnecessary to speak further, but more especially to notice the phenomena of wind-storms or hurricanes, which occur with much irregularity in various warm climates, and whose effects, diminished in intensity, we not unfrequently feel in northern latitudes in March, and towards the latter part of September. This will form an appropriate sequel to the previous article on "thunder-storms," or storms accompanied by electrical ts discharges.

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The law of storms" has been the object of great attention during the last few years; or, in other words, great efforts have been made to discover the circumstances under which wind-storms, or hurricanes, arise, and to obtain observations of the phenomena which they present. At first sight their action and occurrence appeared irregular, and we might almost say capricious; but the laws of the universe were ordained from the beginning, and nothing can be accidental. The phenomena which seem the most irregular are often found to be, in fact, the very reverse; and "exceptions," over and over again, "have proved the law." As an example of this we might note how the aberrations of the planets at first appeared to disprove the Newtonian theory, but were, upon examination, found to show that gravitation was a universal principle, and that the views of Newton were beautifully confirmed by that which was adduced as an exception. For a long period the law of storms assumed no very definite form, the question of chief difference being whether wind-storms or hurricanes were direct currents or great whirlwinds. It is, however, now generally admitted that, though there may be currents of air passing over portions of the earth's surface with great rapidity, such wind-storms rarely or never do much mischief, or assume such violent characters as those wind-storms which are of a circular form, or whirlwinds. "The general phenomena of these storms will be understood if the storm, as a great whirlwind, be represented by a circle whose centre is made to progress along a curve, the circles expanding as they advance from the point at which the storm begins to be felt-the rotatory motion, in the northern hemisphere, being in the contrary direction to that in which the hands of a watch go round."* In the southern hemisphere the rotatory motion is in the opposite direction.

It appears that the East India fleet and other vessels, in 1809, experienced a dreadful storm in latitudes near the Cape of Good Hope. "Some of the vessels scudded and ran in the storm for days; some, by lying-to, got almost immediately out of it; while others, by taking a wrong direction, went into the heart of it, foundered, and were never heard of more; others, by sailing right across the calm space (in the centre of the whirlwind), met the storm in different parts of its progress, and the wind blowing in opposite directions, and considered and spoke of it as two storms which they had encountered; while others, cruising about within the bend of the curve,

* Lieut.-Col. Reid's Paper read to the British Association, 1838.

K K

but beyond the circle of the great whirl, escaped the storm altogether."* To explain this more clearly, let us request the reader's attention to the diagram. Let the plane surface of the paper represent the surface of the sea, and a line through A 1, perpendicular to it, represent the axis of a whirlwind, whose north and south diameter is represented by the line N S. To realize this idea, place the point of a pencil on the point A 1; when the pencil is held in a vertical position it represents the axis of the storm's motion. The particles of the air are supposed to revolve in the direction

XM5

Mi

M3

E.

A1

M4

S.

indicated by the order of the letters NWSE; the axis is, moreover, As supposed to have a progressive motion from A 1 through N. Now, it will appear that since at N a tangent to the circle lies due east and west, a ship at that point would experience a wind blowing from the east when the centre of the storm is at A 1; and that the wind will continue to blow from the same quarter till A 1 arrives at N; but after that period the wind will appear to blow in the opposite or westerly direction, till the remaining portion of the storm has passed over that point N. In the same manner, if the axis of the storm were supposed to move from A 1 to W, it is plain that at first a ship at the latter point would experience a north wind and would continue to do so till the axis of the storm had passed over it, after which it would be exposed to a southerly wind in the second half of the storm. Suppose, however, that the axis of the whirlwind progressed from A 1 to A 5, and that the storm took a north-easterly direction instead of a course due north, and that, moreover, while the rotatory motion continued in the same direction, the ship remained stationary at some point, as M, till the storm had passed over it; then the line of direction in which the points of the whirlwind successively overtake the ship being M 1, M2, M3, M4 M 5, parallel to A 1, A5, the arcs a M 1, 6 M 1, &c., will indicate the several directions in which the wind will blow upon the ship during the storm. Or, to explain this in more popular terms, the storm passing in north-easterly direction first comes to the ship at M 1, and then blows from the south-east in the direction a M; when the storm has passed over the ship till it occupies the position represented by M 2, the wind becomes almost due east, in the direction represented by 6 M 1; when the storm has advanced still further, and the ship assumes the relative position of M 3, the wind becomes north-east, or blows in the direction of c M1; the wind would then appear to veer round gradually to due north, north-west by north, and at M 4 would blow from the north-west. In fact, to a ship at the point M 1, over which a hurricane, whose centre was successively at A 1, A2 A 3, A 4, and A 5, the wind would blow in the different directions indicated by a b c d and e.

*Redfield's "Observations on Storms."

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By a complete knowledge of the law of storms the experienced captain can so guide his vessel as to avoid the storm altogether, or to keep in its rear. The study of this subject is, therefore, essential to safety in navigation.

Many of our readers will have observed how, in calm weather, sand and dust are carried by the wind with a whirling motion through the air, and that, on the approach of a storm, larger whirlwinds carry up sand and dust into the air. But rotating hurricanes seldom appear beyond the tropics, the though it is believed that all our violent wind-storms have a rotatory motion. The devastations occasioned by them in the hotter climates, where sudden condensations of vapour give rise to the rushing in of opposing winds, and thus originate whirlwinds, are truly frightful. Thus, for instance, in the memorable tornado which desolated Guadaloupe in 1847, solidly-built houses were torn up, and their parts thrown to considerable distances; cannons were hurled from the top of the parapets of the batteries on which they were placed; and it is related that a plank of about three feet in length, eight inches in breadth, and ten lines in thickness, was propelled by the air with such force that it perforated the stem of a palm-tree seventeen inches in diameter.

It has been observed that the progressive motion of whirlwinds is from the equator towards the poles; and by this fact the observer may ascertain his position with reference to the storm. This fact has thrown a curious light upon the question of the nature of the spots on the sun, which, it is well known, take the same direction from his equator to his poles as our earthly whirlwinds. It having been decided that the luminosity of the sun depends upon his atmosphere, there is little reason to doubt but that the spots are the centres of solar hurricanes, from which the radiant medium is thrown by the centrifugal force produced by the rotatory motion.

CHAPTER X.

OCTOBER.

"Grey mists at morn brood o'er the earth,
Shadowy as those on northern seas:
The gossamer's filmy work is done,
Like a web by moonlight fairies spun,
And left to whiten in the breeze.

"Far sails the thistle's hoary down;

All summer flowers have pass'd away;
This is the appointed time for seed,

From the forest oak to the meanest weed

A time of gathering and decay."-MARY HOWITT.

THE summer has indeed gone. The bright tints of gay flowers have faded, and the motley garb of the woods speaks only of maturity and decay. The leaf, the flower (and shall we not add-man?), each serves a purpose in the world, and, having more or less perfectly accomplished it, departs. Solemn thoughts are suggested by the accession of autumn-the falling of the leaf, the mist-hung scenery, and fading vegetation; for there is enough of the poetic temperament in the majority to apply the analogy to human

life, "which groweth up like the grass, and to-morrow is cut down and withered."

The swallows, like the flighty ambitions of our youth, or like false friends, have departed. For days before they leave us they may be seen assembling on church towers, elevated buildings, or willow plantations by the river sides. At first a few only perch, and, like touters for steam-packets, loudly scream that the company will start from that particular locality. Presently, high wheeling above our heads, we may see a thousand of their fellows, apparently in a high degree of excitement, screaming to each other as if they were determined to enjoy a good frolic before finally leaving the pleasant scene, and entering upon their long and dangerous journey. Gradually, towards sunset, we have seen them come down like a shower of birds, and blacken the point of rendezvous, where they rest till early morning, where we look for them in vain. Indeed, there appears something magical about their disappearance; for upon several occasions having observed their assemblage at nightfall, we have risen with the grey light of morning to see the host depart, but the travellers have always been up before the sun, and out of sight before we reached their rendezvous.

It has been remarked "that no living creatures which enliven our landscape by their presence excite a stranger sympathy in the lovers of Nature than migratory birds. They interest the imagination by that peculiar instinct which is to them chart and compass, directing their flight over continents and oceans to that one small spot in the great world which Nature has prepared for their reception-which is pilot and captain, warning them away, calling them back, and conducting them in safety on their passage; that degree of mystery which yet hangs over their motions, notwithstanding the anxious perseverance with which naturalists have investigated the subject, and all the lively and beautiful associations of their cries and forms, and habits and resorts. When we think for a moment that the swallows, martins, and swifts which sport in our summer skies, and become cohabitants of our houses, will presently be dwelling in the heart of regions which we long in vain to know, and whither our travellers toil in vain to_penetrate; that they will, anon, fix their nest to the Chinese pagoda, the Indian temple, or beneath the equator, to the palm-thatched eaves of the African hut; that the small birds which populate our summer hedges and fields will quickly spread themselves over the regions beyond the Pillars of Hercules, and the wilds of the Levant, of Greece, and Syria; that the thrush and the fieldfare, which share our winter, will pour out triumphant music in their native wastes, in the sudden summers of Scandinavia-we cannot avoid feeling how much of poetry is connected with these wanderers of the earth and the air."

The swallows are a family of birds living upon insects, and in which the powers of flight attain their highest development, while the feet are com- İ paratively useless for the purposes of locomotion. It occupies different positions in various classifications. The European species of this family are the "true swift," the "white-bellied swift," the "rock martin,” the "rufous swallow," the "martin,” and the "sand martin.” The true swift, the rufous swallow, the martin, and the sand martin visit_Britain in the summer time; the rest rarely or never come to our shores. In the true swift the leg is thickly feathered almost to the claws, and all the four toes are directed forwards. It will be seen from this that the swift cannot perch

upon a bough or take hold of anything: its foot is in the same predicament that our hands would be if the thumb were removed. This beautiful creature comes to this country early in May, and leaves us towards the end of August. It comes the latest and departs the soonest of its tribe. It is the largest of the swallows which visit us; but its weight is exceedingly small when compared with its extent of wing-the former being scarcely an ounce, the latter nearly eighteen inches. Owing to the peculiar conformation of the feet to which we have already alluded, and which are smaller than in any other of its own species, it walks upon the ground with diffiulty, and finds it almost impossible to rise, because its feet render it no assistance in springing, and its wings and tail are so long as to beat the earth, and thus become less an aid than an impediment.

We remember, a few summers ago, that a swift having been caught in its nest, was placed upon a grass-plat, and found itself quite unable to escape. It was suspected that its wings had been injured, or that some violence had been done to it in its capture; but, upon examination, no such calamity ppeared to have befallen it; indeed, while the question was being discussed, the swift took flight from the hand with perfect ease, and like an arrow darted up into its natural element, the air. It was remarkable that the nest, which was within reach of the window, was not forsaken by the bird, even though the graceful aëronaut was repeatedly caught at night in its place of roost.

The swift is more upon the wing than any other swallows, and its flight is more rapid; hence its name-"swift." As it wings its graceful course it seems to announce its joyousness by a screaming of peculiar shrillness. It rests by clinging against a wall, and breeds under the eaves of houses, in steeples, and other lofty buildings, where it constructs its nest of grasses and feathers, and lays two long white eggs. Its colour is a dark glossy black, the chin only having a white spot upon it. It was a popular superstition at one period that there was in India a bird which had no feet, lived upon celestial dew, floated perpetually on the air, and performed all its functions in that element. Referring to this, Mr. Pennant says, "The swift actually performs what has been disproved of the bird of Paradise; except the small time it takes in sleeping, and what it devotes to incubation, every other action is performed upon the wing." The materials of its nest it collects either as they are carried about by the winds, or picks them from the surface of the ground. Its food is undeniably the insects which fill the air. Its drink is taken in transient sips from the water's surface. These wonderful birds rise very early and retire to roost very late, remaining in incessant activity during the long summer days. A pair whose motions we observed some years ago were on the wing, on more than one occasion, from a little after four in the morning till nearly nine o'clock at night. Those residing in a particular neighbourhood seem to assemble like human families before bedtime, and shrilly wish each other "Good night" in the high air, and forthwith, with one accord, to come down to their nests. Great power of sight is, of course, indispensable, both to enable the bird to obtain its food and to insure its safety in its rapid flight; but this power is not always sufficient to guard it against accident. Mr. Yarrell relates that he saw a swift, on eager wing," dash itself against a wall; it was picked up stunned, and died almost immediately in the hands of the observer. In its northward career its visits are not confined to England, but extend to the

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