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home for boarding-school, nor encourage 66 manlin ess " at the expense of brotherly affection, and do not grudge an hour bestowed upon a little pains-taking letterwriter or juvenile composer, who is anxious to give an account of various home details to the absent one. Let him write two or three sentences of his epistle each night, overlooked by an elder sister; the one will feel happy at being able to instruct, the other will be grateful at the sight of the letters that grow beneath his pen. By any means, at any expense of trouble to

yourself, make home happy to your children; let it always remain in their memories as a type of all that is peaceful, loving, and attractive; let them constantly revert to it as a soothing remembrance in the hours of pain, sorrow, or privation, and let its associations be so hallowed and precious as to restrain them in temptation and strengthen them in trial. Yours is a noble mission; O parents! see that ye fulfill it with that wisdom and gentleness which shall prove you worthy of the dignity and honors it confers!

PHENOMENA OF ELECTRICITY.

THERE are two kinds of electricity; the one vitreous or positive, the other resinous or negative; and both kinds are produced in the atmosphere by various causes; chiefly by evaporation. We may form a slight idea of the extent of evaporation carried on over the whole globe-over all the rivers and lakes and seas, the stagnant pools and latent moisture, the hidden springs and boundless oceans-when we remember that three hundred millions of hogsheads of water rise daily into vapor over the Mediterranean alone. By condensation, or the change which that evaporated vapor undergoes when returning to a fluid state through decrease of temperature; by vegetation, by combustion, and by friction. This last arises when masses of air, moving in contrary directions, encounter each other. The friction of their surfaces develops electricity, which is especially active when these masses differ in degrees of moisture and temperature; the cold developing negative, and the warm positive, electricity. The friction of the wind, as it passes over trees, houses, mountains, and other high objects, is also held to set free the electricity of the atmosphere; so that we can understand why thunder-storms should be almost always accompanied by strong winds, and should rarely or never occur in perfectly still weather.

Clouds charged with electricity of one kind meet and coalesce in good fellowship enough; but, when those which bear a different kind meet together, a violent shock is the consequence. Rains are formed by the meetings of different winds, as thunder-storms by the contact of opposing_electricities. A warm soft air, charged with moisture, meets with a cold wind direct from the polar regions. The cold north wind condenses and globulates the vapor, which falls to earth in the form of Scotch mists or showers.

First, before a storm arises, is scen the cirrhus; that light fibrous curl-like cloud, which stretches in undulating waves or long lines over the sky, sometimes curling out like the lightest and most graceful feathers, or like the sweeping grain of knotted woods. This broadens out into the cirrhocumulus, or sonder cloud; those little round masses which lie near together but yet separate, and give the mottled or speckled skies which are so beautiful in summer afternoons when they bode no mischief and contain no evil. Then the cirrhocumulus gathers itself into the cumulus proper, or strachen-cloud-large heaped-up masses that look like carved marble or sun-covered boulders in the deep blue-sky-those dazzling white day clouds which children gaze at wonderingly as if they were solid masses built up in

the heavens, and which even older brains a quarter. As sound travels three huncan scarcely credit to be mere impondera- dred and seventy-five yards per second, ble vapor. These are the forerunners of the distance of time elapsing between the the storm cloud; that dark, gray, rugged flash and the report may be taken as a mass, with its sharp and jagged edges, basis for calculation by any one with from which stream down both health and nerve sufficient to time a thunder-storm by destruction to the world below; that the hand of his watch. cloud, darker and more threatening than the nimbus or rain-cloud, with which people, who are not good observers, so often confound it.

Storms never come from the perfectly uniform and regular clouds which sometimes cover all the sky. Storm clouds have always torn and angry edges, as one would expect from them, fierce and riving as they are instruments of death, and among nature's earliest embodiments of rage and devastation. Storms are many patterned. Franklin says that a thunderstorm never comes from one cloud only, and Saussure agrees with him; but other meteorologists (notably, Bergman and Duchamel de Monceau, good names enough) assert the contrary; and Marcovelle states, that on the twelfth of September, seventeen hundred and fortyseven, the sky at Toulouse was perfectly clear except for one little cloud, from which suddenly burst a thunderbolt that killed a woman named Bordenave as she stood before the house. If that unhappy femme Bordenave bore but an indifferent character-if sorcery and the black art were included among her gifts-we may be sure how the occasion was improved by all the anti-witchcraft world; and how an inevitable natural law was translated into a signal act of Divine vengeance, calculated to strike terror into the hearts of all the sabbet-haunters, loup-garous, broomstick-riders, black cat keepers, and familiar nourishers in Toulouse.

As storms always commence with the accumulation of the cirrhus-cloud, and as the cirrhus-cloud floats very high, it follows that storms are generally very high above the earth. Kametz, one of the greatest meteorologists, doubts all the travelers' tales which set forth how they, the travelers, journeying over the Alps and the Brocken, have seen storms forming below them. Yet Monsieur Abbadie found in Ethiopia that an October storm was only about two hundred and thirtythree yards above the earth; but the highest which he noted was one in February, at about two thousand two hundred and forty yards, or about a mile and

Pliny says it never thunders in Egypt. Plutarch that it never thunders in Abyssinia. We know now that both of these assertions are mistakes, though indeed Egypt is singularly exempt from frequency of storm; for storms are correspondent with rains, and, as it seldom rains in Egypt, thunders and lightnings are equally rare. It never rains in Lower Peru, or so rarely as to be outside all meteorological consideration; consequently, say at Lima, storms of thunder and lightning are as little known as hurricanes of wind and rain. Storms are also rare at the North Pole, and never occur in mid seas, at a certain distance from land. The rainy days at Cairo are only three or four in the year, the storm days are about the same number. At Calcutta the average of storm days is sixty, and every where a broad parallel is kept; so that, where there is most rain, there is also most thunder and lightning. Storms come at the same times and seasons, and with striking regularity. In the tropics they accompany the wet season and the change of the monsoons; at Calcutta, with its sixty days of storm, not one occurs in November, December, or January; at Martinique and Guadaloupe none are known in December, January, February, or March. In mean latitudes, very few storms occur in winter, and only a few in the hottest days of spring and autumn: more than half come in summer, and generally in the day-rarely at night, either in the tropics or in the temperate zones. But the rule of summer storms does not hold absolutely for all places; for, on the western coast of America, and the eastern shores of the Adriatic, more occur in winter than in summer; in Greece more in autumn and spring; in Rome there is no difference between summer. and autumn; at Bergen and at the Azores, where there are winter rains, they are most frequent in the cold and rainy. weather; at Kingston in Jamaica it thunders every day for five consecutive months, though the adjacent islands are tranquil; also at Popayan in Columbia during a certain season, there is thunder every day.

Woods, mountains, and broken land cause and attract storms; but their frequency is not always referable to the configuration of a district. At Paris, for instance, the average number of thunderdays is fourteen; and Paris is not on a dead level; while at Denainvilliers, between Orleans and Pithiviers, one of the flattest districts possible, the average is raised to twenty-one. Other atmospheric causes, then, must be in operation which are not yet made fully manifest, and which remain to be investigated.

There are three kinds of lightning, says Monsieur Arago; forked, sheet, and spherical. Forked lightning comes in very slender flashes, generally white, but is sometimes blue or violet colored. Fine as these flashes are, they often divide into three or more branches: as, when in seventeen hundred and eighteen, twentyfour churches were struck in the environs of Saint Pol de Léon, but only three peals of thunder were heard. The flashes of forked lightning are most destructive. They are no where seen to more terrible perfection than when lighting up the dark ravines and black precipices of a mountainous district. Even in England, among the Cumberland mountains, the thunderstorms have a majesty and awful sublimity which no dweller on the plains can understand. Sheet lightning is comparatively harmless. Some of those thunderless summer lightnings are distant sheet lightnings, too distant to allow of the thunder, which yet exists, being heard. Dark red, blue, or violet are the principal colors of this form of electricity, which has neither the whiteness nor the swiftness of the forked. Spherical lightnings are what are called vulgarly, thunderbolts; luminous masses, or fiery globes, which descend slowly to the earth, and make lightning conductors useless. On the night of the fourteenth of April, seventeen hundred and eighteen, Deslandes saw three globes of fire fall on the church of Couesnon near Brest, and destroy it utterly; and, on the third of July, seventeen hundred and twenty-five, during the hight of a thunder-tempest, an enormous globe of fire fell, and killed a shepherd and five sheep. This was not so terrible, though, as the Ethiopian storm, reported by Abbadie, which destroyed two thousand goats and the goat-herd by one single flash. We quote these assertions modestly, if somewhat

doubtfully; not presuming to place a limit to the wonderful forces of nature, of which the more we learn the less we seem to know, yet expressing ourselves humbly on the uncertainty of testimony, and the proneness to exaggeration common to humanity. The balance between skepticism and credulity is the most difficult of all balances to hold evenly.

Those summer lightnings, of which we have spoken, have been taken by some to mean essentially harmless interchanges of electricity; the atmosphere seeking its own electrical equilibrium. But it will generally (not always) be found that, during their appearance, there has been a storm somewhere on earth, where, what was but lambent summer lightning to the far-off spectator, has proved to be deadly destructive fire to some hapless dweller underneath. In a July night of seventeen hundred and eighty-three, De Saussure, at the Hôpital de Grimsel, under a calm clear sky, saw, in the direction of Geneva, a thick band of clouds, which gave out thunderless lightnings. This was but summer lightning to him; but the Genevese were suffering all the horrors and ravages of a storm such as the oldest inhabitant had never witnessed. And in eighteen hundred and thirteen, Howard, at Tottenham, saw, on the south-east horizon, and under a clear starry sky, some pale summer lightnings, which proved afterwards to be a violent storm raging between Calais and Dunkerque. The question of distant storms, and how far the reflection of them could be possibly visible, and whether this sheet or summer lightning necessarily always argued a distant storm, was being once discussed at the philosophical society of Geneva. When the meeting broke up, the southern horizon was illuminated with the very form of lightning under dispute. Some days after, the newspapers spoke of a violent storm in the Pays de Vaud, Wurtemberg, and Bavaria; which seemed conclusive enough as to how far reflection could be carried, if not as to the universally uniform character of distant sheet lightning. For there are, in truth, such things as thunderless summer lightnings; lightnings without storms and without dangers; and as frequent under the tropics as in our own temperate latitudes. There is probably, and more than probably, thunder with these flashes, but at too great a hight from us to be heard.

Besides, the higher the atmosphere, the | quency of thunderbolts there. Even while more rarefied it becomes, and the more Monsieur Boussingault was crossing El rarefied the medium, the less intensity Sitio, the black who guided him was there is of sound; but we can scarcely struck by lightning. La Loma de Pitago, imagine that lightnings can be inter- near Popayan, is another locality of doubtchanged without any accompanying re- ful electric fame. A young botanist, port, or that a certain law of nature can be Monsieur Plancheman, was determined to contravened, without the intervention of cross La Loma on a stormy day, in spite any higher agency, or the interruption of of all remonstrances, and was struck dead an opposing law. by a thunderbolt. On the twenty-ninth of June, seventeen hundred and sixty-three, a thunderbolt struck_the_bell-tower of a certain church near Laval, and, entering the church, caused great damage; on the twentieth of June, seventeen hundred and sixty-four, a thunderbolt struck the same bell-tower, entered the church, and melted the same gilding, blackened the same holy vessels, and in the very same spot as the preceding year, made anew two holes which had been filled up. There is no more striking instance on record of the uniform action of natural laws than this. We believe, too, that any inhabitant of a mountainous district could bear out our own assertion and observation, that where once a thunderbolt had been seen to fall, or forked lightning to strike, there surely would the same accidents occur during the worst storms of succeeding years. We may be certain that there is no such thing as chance in nature. Chance is simply our ignorance which can not foresee necessary consequences, because it does not understand the foregoing laws; there is no such thing as blind unmeaning hazard, without necessity and without law.

There being lightnings without thunder, so there are thunders without lightning. Volney, among many other witnesses of similar phenomena, speaks of violent thunderings one morning at Pontchartrain, under a clear sky, and without lightning; but, in a quarter of an hour the heavens clouded thickly over, and a heavy hailstorm fell, the stones as big as his fist. The longest thunder roll (which seems so interminable to those who are nervous during storms) lasts only from thirty-five to fifty seconds; and the space of time between the roll and the flash varies, according to distance, from five, four, three, and even half a second, to forty-two, forty-seven, forty-nine, and seventy-two seconds. But the half-second interval is very rare, and only found in storms of the closest and most violent character. We need scarcely add, that the nearer a storm, the more dangerous. Also, the higher the body the more likely it is to be struck; as, for instance, all mountains, trees, high buildings, and, in the midst of a plain, men and animals. Trees, bushes, and buildings are peculiarly lightning conductors, and specially liable to be struck. For this reason it is wise to avoid the neighborhood of trees during a storm; not even trusting to the old poetic legend of the exemption of all the laurel tribe, for love of one fair Daphne; nor to Hugh Maxwell's assertion that the beech, maple, and birch are anti-conductors, like that classic laurel; nor to Captain Dibdin's belief in pines; nor, in fact, to any private or personal favorite among forest-trees or shrubs; for they are all equally dangerous to human neighbors during a storm, and equally powerful conductors; their power varying only as they are taller or more humid than their fellows.

Thunderbolts have special attraction to certain places as well as to certain objects. No one in New-Granada, says Monsieur Arago, willingly inhabits El Sitio de Tumba Barreto, near the gold mine of the Vega de Supia, because of the fre

Chemical, mechanical, and physical ef fects follow on electrical phenomena; which, any one may see repeated, on a minute scale, by an electrical machine. Lightning melts and vitrifies masses of rocks, sometimes covering them with a yellowish green enamel, studded with opaque or semi-transparent lumps. But it has never been known to melt any metallic substance of a certain thickness. Watchsprings, small chains, points, and parts of swords and daggers, fine lines or threads of metal, or thin layers and washes, these have been known to have been thoroughly melted by a lightning stroke. Larger masses, heavy chains, and the like, have been softened and bent, and twisted, but not melted.

Beyond the thunderbolts of ordinary talk-which means simply lightning-flashes that strike the earth there are real

and actual thunderbolts found in several | lyzed forever. The church was filled with parts of the globe; ponderable and tangi- a thick black smoke through which the ble bodies; masses filled inside with a only light to be seen was from the flaming smooth and brilliant glass, something like of the burning clothes of the poor creavitreous opal, which cuts glass and strikes tures struck. A young child was torn fire by a steel. These bodies having been from its mother's arms, and flung about subjected to an ignominous disclaimer, six paces from her; a youth, at that moMonsieur Hagen, of Königsberg, came ment chanting the epistle, felt as if seized forward as their demonstrator. During by the throat, and then was flung outside a storm at Rauschen, a thunderbolt fell the church-door; the missal was torn on a birch-tree, leaving two narrow and from his hands, and riven to pieces. All deep cavities in the ground near the tree. the dogs in the church were killed as they Monsieur Hagen, digging very carefully lay or stood; and the officiating priest round one of these cavities, came upon a alone, clothed in silk, received no hurt. perfect thunderbolt: a pearly-gray, vitre- The dogs were all killed, as we said, for ous mass, covered with small black spots. | lightning strikes animals in preference to The wonderful chemical changes and de- men; and numberless instances are to be compositions which electricity makes in met with of animals which have been all organic bodies are too technical and struck, and human beings left harmless, in too numerous for description here. a storm, though perhaps the horse has had a rider, the ox a driver, the cow a milker, and the dog a master in the act of caressing him, as the lightning fell. Nothing, indeed, is so inexplicable to us as the choice which the lightning seems to make. Among a crowd of persons perhaps one or two will be struck and the rest saved; between two, one will lie dead not five feet from the other, left unharmed. In a stable where there were thirty-two horses in a line, those at the two extremities only were touched. The lightning passed innocuous over the intervening thirty. This was at Rambouillet, in seventeen hundred and eighty-five; and, in eighteen hundred and eight, at Kronan in Switzerland, five children were sitting in a row on a bench, when a thunder-storm broke out, and a flash of lightning killed the first and the last, leaving the center three unhurt, beyond a somewhat rough shaking. And of five horses in a line, the first and last two were killed, while the middle one, an old blind Dobbin, ate his hay without molestation. But this is a well-known electric law, if not a well-understood one; the first and last in a chain always feeling the shock the most powerfully, while in a metallic tube there is always most damage and most impression where the lightning or electric current has made its ingress and egress.

The mechanical effects of electricity are tremendous. Trees torn up by their roots, large masses of rock hurled great distances, houses flung to the ground like packs of children's cards, roofs and walls and furniture strewn in a helpless medley together, are a few of the ordinary mechanical effects of lightning, when it strikes any thing on earth. Under the physical effects are ranged the carbonization or burning of combustible bodies; the wonderful manner in which trees are sometimes barked, and the wood rendered friable, and like dust; in animals, the loss of sight and hearing; paralysis, and apoplexy; though this last group ought rightly to be ranked under vital or pathological effects.

The most terrible storm on record is, perhaps, one which occurred at the small village of Châteauneuf les Moustiers, in the department of the Basses-Alpes. During service, the village church was struck by three masses of fire, falling in succession. Nine people were killed, eighty-two were wounded; all had paralyzed limbs, as well as other maladies. The cure of Moustiers, who had come over to assist at mass, was found, after the first confusion had subsided, lifeless, scarred with numerous surface wounds, and paralyzed. His garments were torn, the gold lace of his stole melted, and the silver buckles of his shoes broken and thrown to the other end of the church. It was with great difficulty that he was recovered, but he suffered from his wounds for two long months, during which time he never slept; and his arms were para

A thunderbolt falling in a powder magazine, sometimes simply scatters the powder about, without setting it on fire, as happened at Rouen on November the fifth, seventeen hundred and fifty-five, and at Venice on the eleventh of June, seventeen hundred and seventy-five. But this

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