sphere; but when it flashes in a short, straight, or direct line of vivid light, it may be considered to have disrupted a comparatively limited portion of the atmosphere.

In the first case the flash would be seen some time before the thunder would be heard, and in the second case the flash would be instantly followed by the thunder.

The tree in the back ground is supposed to have determined the discharge of lightning from a cloud hovering at a considerable distance, the flash is therefore long and irregular, and a spectator of the storm, if standing near the tree, would first hear the thunder from the collapse of the air near its summit, then from beyond this, afterwards from a more remote portion, and ultimately from the volume of the cloud, whence the lightning first broke forth; the thunder, therefore, would not fall upon the ear as one direct and crashing

sound, but as an irregular succession of sounds, or loud rumbling noise.

"This irregularity in the passage of lightning, is sometimes so considerable, that the thunder is actually lost to the ear at one moment, and heard again at another, and this three or four times successively in the same clap ;" and this, conjoined with the reflection of the sound, or its reverberation from mountain, hill, and valley, at one instant, pealing loudly, at another, booming gently, at length murmuring faintly, and ultimately dying away, are extremely impressive concomitants and attendants of the original phenomenon of the flash.

The tree in the fore-ground of the engraving, is supposed to have determined the discharge of lightning from a cloud hovering at a little distance, the flash is therefore short and regular, and a spectator of the storm, if standing near this tree, at the moment of the flash, would hear the full thunder of the collapsing air, as one loud and terrible crash, which in a few seconds after, would reverberate from surrounding objects, and ultimately die away in silence.

When the chemist causes electricity to pass through large and small intervals of air, the vivid sparks in their disruptive transit, present upon a microscopic scale appearances precisely similar to those of extensive and limited flashes of lightning.

An appearance of two distinct flashes or streams is very frequently produced at a considerable distance from each other, when part of a long, sharp, angular

flash is hidden by an intervening cloud, and the sudden and universal flash, or "sheet lightning," appears to result from a discharge which is more perfectly concealed.

The bright flashes which occur during summer and autumnal evenings, unaccompanied by thunder, are of this kind, and it is supposed that on account of their vast distance from the earth, that the sound of the thunder must be lost in its passage.

"The appearance of the heavens during a thunderstorm, the manner in which the clouds assemble, and attract and repel each other, the circumstance of their rising against the wind, and traversing the upper regions of the atmosphere in a variety of contrary directions, are phenomena, which it is not difficult to explain by reference to the general laws of electricity."

Many of these have been discovered by the great philosopher of the present day, and regarding his extraordinary knowledge of Electricity and Chemistry it has been justly said, that "in point of originality in devising experiments, skill in carrying them into effect, and perspicuity in tracing out, and unravelling the complicated relations of the new truths which are elicited, he stands, if not unrivalled, at least unsurpassed."

Upon known laws of electricity, as excited in the laboratory, the peculiar fringed appearance of a thunder-cloud may be explained, and also the irregular portions which it projects towards the earth, whilst its upper surface is generally smooth, and well-defined.

"We sometimes observe that a number of such

clouds of small dimensions, coalesce into a larger one, moving swiftly in all directions, and darting flashes from one to the other, whilst the wind rises and often blows in squalls; the lightning is more frequent as the clouds aggregate, and a great expanse of the heavens often appears in an almost continuous blaze of light; the thunder at first rumbling in the distance, now approaches with various roaring and rattling sounds, and the rain often falls in torrents.

"If we watch a severe thunder-storm from the beginning to the end, we observe a singular variety in the appearance of the flashes; the scene is sometimes rendered awfully magnificent, by their brilliancy, frequency, and extent, darting sometimes in broad, welldefined lines from cloud to cloud, and sometimes shooting towards the earth, they are often zig-zag and irregular, and sometimes are said to appear as a large and rapidly-moving ball of fire, an appearance usually designated by the uninformed, a thunderbolt,' and erroneously supposed to be attended by the fall of a solid body."

Thus the nodular masses that are so frequently found on the sea beach, at the foot of chalk cliffs, are called "thunderbolts," yet they have not fallen from the heavens, but from the cliffs, and when chemically examined, are found composed of sulphur and iron, they are" sulphurets of iron" therefore, and if two masses be violently struck against each other, sparks of fire appear, in consequence of the heat of the blow or collision having enabled both elements to attract

oxygen from the air and burn; thus fire was anciently obtained, and the name of " pyrites," or "fire-stone, was likewise conferred upon the supposed "thunderbolt." But let us continue our investigation of the "thunder storm."

"The voice of the Lord is upon the waters: The God of glory thundereth: The Lord is upon many waters.” "The voice of the Lord is powerful; the voice of the Lord is full of majesty."

In such sublime and rapturous exhortation to the princes of the earth, does the Psalmist set forth the glory of The Omnipotent Ruler of the storm; and regarding its awful and astounding grandeur, no man can either feel, or feign indifference; yet he does well,that instead of indulging in morbid fear, and of communicating it to others, endeavours to calm such emotions, by reflecting and expounding that the will of God directs the storm, to remind us of our insignificance, which in the pride of our knowledge, and the height of our abundance, we are but too prone to forget.

It is, however, the imperative duty of every man to exercise his utmost reasoning and inventive faculties for guarding his life, and the lives of others, against the physical power of the lightning, and not with impiety and presumption to defy the storm.

In the open air, shelter should not be sought immediately under a tree or building, for should they be struck, such a situation is particularly dangerous, if not fatal; the distance of twenty or thirty feet from tall