Gatherings of Science. THOUGHTS FOR YOUNG THINKERS. We still defer the replies to the May questions to next month. THUNDER-STORMS. A THUNDER-STORM usually happens in calm and sultry weather. A low, dense, and dark cloud begins to be formed in a place previously clear; it increases rapidly in size and apparent density, and attracts to it other clouds in its neighbourhood. Its upper surface appears of an arched form like great bags of cotton, while its lower surface is commonly level, as if it rested on a glass plane. Soon after appear numberless small, rugged clouds, like flakes of cotton. These move about in all directions, and are continually changing their ragged shape. During this confused motion, the whole mass of small clouds approaches the great one above it, and, when near it, the clouds of the lower mass frequently coalesce with each other before they finally coalesce with the upper cloud. The heavens now begin to darken apace, the whole mass sinks down; wind arises, and frequently shifts in squalls; small clouds are seen moving swiftly in various directions, and the lightning now darts from cloud to cloud, and from one part of the cloud to another, so as to illuminate the whole mass. When the cloud has acquired a sufficient extent, the lightning strikes the earth in two opposite places, the path of the lightning lying through the whole body of the cloud and its branches. A continuation of these discharges of electric matter rarifies the cloud, and in time it dissipates. This is accompanied with heavy rain, and sometimes with hail showers; and then the upper part of the clouds becomes high and thin. During thunder-storms the lightning frequently assumes different forms, and is sometimes very terrific. The most formidable and destructive form which lightning is ever known to assume is that of balls of fire. The motion of these is often perceptible to the eye; but wherever they fall, much mischief is occasioned by their bursting, which they always do with a sudden explosion like that of a musket or cannon. Sometimes they quietly run along, or rest for a little upon anything, and then break into several pieces, each of which will explode, or the whole ball will burst at once, and produce its mischievous effects only in one place. By the action of these balls, houses, corn-yards, and other combustible materials, have been set on fire and consumed, and when cattle or human beings have been in their course, they have been instantly killed. Next to this kind of lightning in its destructive effects is that of the zigzag kind, which most frequently accompanies a thunder-storm. Some times this species of lightning makes only one angle like the letter V; sometimes it has several branches, and sometimes it appears like the arch of a circle. The third species of lightning is generally known by the name of sheet lightning. This kind of lightning has a kind of indistinct appearance, without any determinate form, like the sudden illumination of the atmosphere, occasioned by firing quantity of loose gunpowder. It is sometimes seen in a serene sky, and is seldom or never known to do any injury. It has also been remarked that the colour of the lightning indicates in some measure its power to do mischief; the palest and brightest flashes being most destructive, while such as are red, or of a darker colour, are found to do less mischief. The general scene of a thunderstorm is the heavens, or the superior regions of the atmosphere; and it is by no means a frequent case that a discharge is made into the earth. The electric fluid discharges itself from one cloud to another, and when the clouds are high in the air there is little danger to objects on the surface of the earth. It is only or chiefly when the thunder-cloud comes within the striking distance of the earth, and the lightning strikes perpendicularly downwards, that the danger is to be apprehended. When the flashes appear parallel, the scene of the storm is in the clouds; but when they appear to dart perpendicularly, the thunder-cloud has descended so low as to be within the striking distance, and all the objects in its neighbourhood are within the limits of danger. The interval of time between seeing the flash and hearing the report of the thunder is generally about seven or eight seconds, which, reckoning sound to move at the rate of 1142 feet per second, shows that the thundercloud is nearly two miles distant. But, should the sound be heard within a second or two of seeing the flash, we may conclude that the cloud is discharging its electricity into the earth, at no great distance, and consequently that we are in the neighbourhood of danger, in which case numerous accidents have happened both to buildings, cattle, sheep, and human beings. Even in our own temperate clime thunder-storms are sometimes violent and terrific, and attended with many destructive effects. Buildings shattered and demolished-trees rent and torn asunder-the hardest metals in a moment dissolved-stones and rocks rent and broken-stacks of corn set on fire-men and other animals knocked down, struck blind, or instantaneously killed-are some of the terrible effects of that powerful fluid which darts through the atmosphere during a storm. Every returning year is generally marked with some affecting instances of this kind in one part of the country or another, and frequently in different districts at the same time. From a register of such accidents which we kept in 1811, it appears, that during the months of June and July that year, within the bounds of seven counties in England, two large oaks were shattered-a windmill and several other houses struck and the walls and windows shattered and | ing the building to its foundations, knocked out walls, windows, and doors, and covered the stunned people with hundredweights of brick, plaster, door-posts, and fragments of rafters. Most of them were found in a state of insensibility, and two or three apparently dead, but were afterwards supposed to be in the way of recovery. The storm which raged on the 1st of August in London and the neighbouring counties was particularly awful and destructive. In the metropolis immense injury was done both to public and private buildings. In Buckingham palace many thousand squares of glass were demolished, amounting in value to nearly £2000. Somerset House, Burlington Arcade, Bakerstreet Bazaar, Paddington Terminus of the Great Western Railway, the Horticultural Gardens, Chiswick, the Botanic Gardens at Kew, and in the Regent's Park, the Westminster School of Medicine, the Houses of Lords and Commons, and a vast number of other public and private buildings, were considerably damaged. At Messrs. Cubitt's factory, Millbank, nearly 14,000 squares of glass were demolished. In most of the surrounding counties, likewise, much damage was sustained-cattle, sheep, and several human beings were destroyed-houses were struck by the destroyed, 4,000 panes of glass broken, 2 cows and 26 sheep killed, besides a great number not particularly specified, eight persons were struck down and injured, and eleven men struck dead,-the shepherd of Mr. Edman, of Marblethorpe, who had his skull shattered to pieces and was rendered a shocking spectacle; two men who had taken shelter in a barn near Stone; a lad at Frome who was working at his loom in the ground floor of a house which was struck, several persons who had taken shelter under trees, &c. In Scotland, during the same period, four or five persons were killed, a considerable number of persons struck down and materially injured, several buildings damaged, and a considerable number of cattle and sheep were destroyed by the stroke of lightning. During the late storms of June, July, and August, 1846, particularly in England, many lives were lost, and immense injury was done to buildings of different descriptions, and vast numbers of horses, cattle, and sheep, were destroyed. The public journals specified from twelve to fifteen or more persons killed by the lightning, besides numbers seriously injured. In a field near Wells, seventyfour sheep were struck down and killed by one stroke of lightning. At a toll-house, near Gloucester, fifty-electric fluid, and partly destroyed— one persons crowded together for shelter, when a flash of forked lightning struck a neighbouring tree, glanced thence into the house in the midst of the affrighted inmates, and exploding with a terrible report, threw them to the ground, and shak stacks of corn were set on fire-the incessant peals of thunder and sheets of vivid lightning were followed by torrents of rain and hail, which produced universal inundations, and caused the rivers to overflow their banks, undermining houses, and In some places the flashes of lightning were emitted from all parts of the horizon, and increased in rapidity and vividness till midnight, when the heavens were in one continual glare, and the thunders bursting over head. Such are some of the tremendous effects of thunder-storms, which occasionally take place, even in our temperate climate. sweeping away the fruits of harvest. | lets, and every mass of water, should be avoided, especially when occurring in elevated stations; because water, being an excellent conductor, might determine the course of an electrical discharge. A person, too, in the open fields should not avoid rain, as it is safer, in a storm, to be completely drenched than otherwise. Persons in a house should avoid sitting near the fire-place, as it brings us in connexion with the highest part of the building, which is most liable to be struck, and as it contains the grate, fender, and fire-irons, which are conducting substances. The bells and the bell-wire should also be carefully avoided, as likewise mirrors, gildings, lustres, and other metallic substances, especially if hanging from the ceiling. The safest position is in the middle of a large room, at a distance from conducting substances; and, if we place the chair on which we sit on a bed or mattress, almost every danger may be avoided.-From Dr. Dick's Christian Philosopher. In order to safety, during a violent thunder-storm, it may be expedient to attend to the following maxims:In the open fields, avoid being under trees, but be near them. Many persons have been killed by being under trees, for the purpose of sheltering themselves from the rain. But to take our station at the distance of forty or fifty feet from a tree or high building is perhaps one of the safest positions during a thunder-storm, as high objects are more likely to be struck, should a discharge from a cloud happen to take place. In the open air, too, rivers, ponds, stream Reviews. SCRIPTURE SITES AND SCENES, Our earth is a sort of consecrated ground covered over with spots of immortal interest, all more or less associated with the glory of God and the ultimate well-being and bliss of man. There is Eden, where man first dwelt and fell. There is Calvary, where man was gloriously redeemed and saved. There is Sinai, where God descended and promulgated his laws. There is Olivet, where Jesus rose to glory and entered on his triumphant rest. And there are all the scenes and sites associated with the ancient history of the an cient church, each one of which is | PRIZE ESSAYS ON THE TEMPORAL now exciting interest in more worlds than one, and mingling itself with the recollections of redeemed spirits or blighted fiends, is giving rise to emotions of joy or grief. The work before us contains graphic descriptions, accompanied by beautiful and well-executed engravings, of some of these consecrated spots. It is professedly confined to scenes of Old Testament interest, leaving those of the New for another volume; but it is replete with interest in every part. Indeed, it has seldom been our lot to review a book which has given us such unmingled pleasure and satisfaction. The descriptions are most instructive, and the drawings, of which there are a great number, very beautiful indeed, and taken by the author on the spot. The author is already well known by two other works, Walks about the City of Jerusalem" and "Forty Days in the Desert in the Track of the Israelites;" but we imagine this will be the more widely circulated work, from its exact adaptation to our Bible class and Sabbath school libraries. It is by far the best work of the kind we have met with, and should at once be secured by all Bible class teachers, as best fitted to give them information and interest their charge in Old Testament scenery. Most able and interesting discussions are scattered through it, with a view to establish the real sites of Scripture reference; and a great deal of new and most useful information to the Bible student is found in every part. We are constrained to pronounce it altogether an admirable work. ADVANTAGES OF THE SABBATH TO THE LABOURING CLASSES, and the consequent Importance of preserving its Rest from all the Encroachments of Unnecessary Labour. By FIVE WORKING MEN. With Prefatory Remarks by the Rev. E. Bickersteth, A.M., Rector of Watton. London: Religious Tract Society. If the present movement in behalf of the Sabbath, and the prizes offered to secure the contributions of the working class, had done no other good than bring out the expression of opinion and feeling respecting the day of rest from so many hundreds of what have hitherto been viewed as the less educated and less thinking of the population, there would have been ample return for all that had been attempted. But these expressions are not mere expressions, they are all arguments, powerful arguments, for the continuance of this holy institution, and amongst the noblest and most effective developments of its untold blessings to our race. All that we have read are excellent, and though each has its peculiar merits and beauties, all are highly creditable to the heads and the hearts of the 1045 who have been engaged in their production. The five here gathered together are all admirable in their way. They are severally written by a porter, a journeyman shoemaker, a compositor, a framework knitter, and a tailor, and form a most interesting and useful little work, which we commend to the perusal of all our youthful readers. |