of the earth, which are locked in perpetual snow and ite, and almost destitute of life, would be much increased."*

It thus appears, that there is a constant circulation going on in the two great fluids of air and water, analogous in some degree to that of blood through the living body, and productive of the most beneficial effects. The manner in which these are attempered and combined is truly wonderful, and has been the subject of philosophical investigation. In regard to the air, Mr Whewell has shown in what manner its composition and laws are adjusted, so as to correspond with, or to counteract and regulate, the different and sometimes antagonist laws of the vapour which constantly circulates through it, and to produce the most salutary effects. This is a question on which I cannot fully enter; but a few observations on the subject of weather, with which it is connected, will occupy our attention to-morrow.

FIRST WEEK-FRIDAY.

THE ATMOSPHERE.

FROM the expansive power of the atmosphere, and the irregular distribution of heat and cold, combined with the inequalities on the earth's surface, arise those storms and tempests which form one of the most forbidding features in the aspect of winter. This may be regarded as an evil; and it is not to be denied, that such elemental commotions are sometimes attended with very disastrous consequences. When the tremendous powers of

nature are in motion, indeed, we might well tremble and despair, did we not know that they are under the guidance of infinite perfection. In rare instances, at long intervals, and in limited spots, we are permitted to witness proofs of the desolation which the uncontrolled elements

* Wheweil's Bridgewater Treatise, p. 82.

might produce, that by the contrast we may be more deeply affected with a sense of the paternal care under which we daily live. We have heard of hurricanes and tornadoes sweeping whole districts with the besom of destruction, of the sirocco and simoon carrying instant death on their poisoned wings,-of mountain torrents and swelling seas bursting their ancient boundaries, and bearing wide desolation in their raging waters,—of thunder rending the heavens, and bolts of fire skathing the earth, of earthquakes swallowing up whole cities, or volcanoes overwhelming them with floods of lava. But these are only the infrequent exceptions to a general rule, which has order and happiness for its object, teaching us at once a lesson of humility and gratitude.

66

If we turn from this view of what might be the uni- · versal state of nature, to real events as they occur under our own eye, and are the subject of daily experience, we shall have abundant cause to acknowledge the presence of an overruling hand. How seldom do we actually observe any extensive desolation produced by a winter storm."All the changes of the weather," Mr Whewell well observes even the most violent tempests and torrents of rain, may be considered as oscillations about the mean or average condition belonging to each place. All these oscillations are limited and transient; the storm spends its fury, the inundation passes off, the sky clears, the calmer course of nature succeeds. In the forces which produce this derangement, there is a provision for making it short and moderate. The oscillation stops of itself, like the rolling of a ship when no longer impelled by the wind. Now, why should this be so? Why should the oscillations produced by the conflict of so many laws, seemingly quite unconnected with each other, be of this converging and subsiding character? Is it a matter of mechanical necessity, that disturbance must end in the restoration of the medium condition? By no means. There may be an utter subversion of the equilibrium. The ship may roll too far, and may cap

size. The oscillations may go on, becoming larger and larger, till all trace of the original condition is lost; till new forces of inequality and disturbance are brought into play; and disorder and irregularity may succeed, without apparent limit or check in its own nature, like the spread of a conflagration in a city. This is a possibility in any combination of mechanical forces. Why does it not happen in the one before us? By what good fortune are the powers of heat, of water, of steam, of air, the effects of the earth's annual and diurnal motions, and probably other causes, so adjusted, that, through all their struggles, the elemental world goes on, upon the whole, so quietly and steadily? Why is the whole fabric of the weather never utterly deranged, its balance lost irrecoverably?"*

The complicated nature of the elements, which enter into the constitution of the atmosphere, renders it difficult, perhaps impossible, to give a distinct answer to these interesting questions, by pointing to the precise law which regulates and controls these elements. Mr Whewell refers to the very peculiar adjustments which we're requisite, and are actually discoverable, in the comparatively simple problem of the solar system, by which its motions have their cycles, and its perturbations their limits and period; and, from this analogy, he conjectures, with much probability, that could the investigation be followed out, it would land us in a similar result. However this may be, it cannot but be regarded as a mark of the interference of an intelligent and beneficent mind, that the intensity of those tremendous forces which are employed in our atmosphere should be so adjusted, as not only to preserve the permanence of the system, but also to be adapted to the existence and comfort of the animal creation.

In adverting to the general properties of that wonderful fluid which envelopes our globe as with a mantle, the distinguished philosopher from whom we have already

* Whewell's Bridgewater Treatise, p. 107.

quoted, makes the beautiful observations, with which we close this

paper.

"If the atmosphere be considered as a vast machine, it is difficult to form any just conception of the profound skill and comprehensiveness of design which it displays. It diffuses and tempers the heat of different climates ; for this purpose it performs a circulation occupying the whole range from the pole to the equator; and, while it is doing this, it executes many smaller circuits between the sea and the land. At the same time, it is the means of forming clouds and rain; and, for this purpose, a perpetual circulation of the watery part of the atmosphere goes on between its lower and upper regions. Besides this complication of circuits, it exercises a more irregular agency in the occasional winds which blow from all quarters, tending perpetually to restore the equilibrium of heat and moisture. But this incessant and multiplied activity discharges only a part of the functions of the air. It is, moreover, the most important and universal material of the growth and sustenance of plants and animals; and is for this purpose every where present, and almost uniform in its quantity. With all its local motion, it has also the office of a medium of communication between intelligent creatures, which office it performs by another set of motions, entirely different both from the circulation and occasional movements already mentioned; these different kinds of motions not inter fering materially with each other; and this last pure pose, so remote from the others in its nature, it answers in a manner so perfect and so easy, that we cannot imagine that the object could have been more completely attain. ed, if this had been the sole purpose for which the atmosphere had been created. With all these qualities, this extraordinary part of our terrestrial system is scarcely ever in the way; and when we have occasion to do so, we put forth our hand and push it aside, without be ing aware of its being near us."

ONE of the curious atmospheric phenomena of winter, the nature of which is not well understood, and still less its use in the economy of Providence, is that shining wa pour which generally makes its appearance in moist weather, in marshy ground, known to the Romans by the name of ignis fatuus, and called by people in this country "Will o' Wisp," "Jack with the lanthorn,” and a variety of other names, all of them indicating the superstitious feeling with which it is associated in the minds of the vulgar. This paper shall be chiefly occu pied with some accounts that have been published of the various appearances which the phenomenon assumes. The first I shall quote is that of a writer in a public journal, who subscribes himself " A Farmer," and expresses himself with such amusing naïveté in describing some of the ordinary vagaries of this reputed sprite, that the homeliness of the style requires no apology.or

"I was riding through a wet boggy part of the road, that lies between my house and the mill, when a little sleety shower, with a strong blast of wind, came sud: denly upon me, and made it so very dark, that I could scarcely see my old mare's white head. I began to cont sider with myself, whether it would be better to turn my back to the storm, and wait till it was past, or take my chance of letting my horse find its own way, when I saw something bright dancing in the air before me. You may be sure I was startled a little at this; for the rain was pouring so fast, and the wind was blowing so strong, that no ordinary fire could stand it; so I whipt up my horse to get out of the way as fast as I could; but to go fast was out of the question, with such an old mare, such a bad road, and so heavy a burden; and, besides, I soon