pounds, all of which may be extracted, and applied to useful purposes, in medicine, arts, manufactures, and domestic economy.

Shells, corals, and other marine productions, are all examined, and their composition ascertained; the animated beings which inhabit the vast and wondrous deep, are discovered to breathe atmospheric air, dissolved in the water so as to suit their peculiar organization. Nor does chemistry pause here in its researches; it discovers that the waters of the gushing spring, or the briny ocean, when freed from earthy and saline impurities, may be changed from the liquid state, and resolved into an explosive mixture of gases. It shows that these, when artfully burned together, produce the most intense heat; and their compound flame is applied successfully in metallurgy and other arts. When urged upon the earth of marble, it evolves "intolerable” light, rivalling that of the sun in the power and purity of its beams; which, directed through proper lenses, enables the naturalist to carry on his researches amongst the atoms of the creation. The sparkling diamond that we prize so highly, chemistry demonstrates to be merely charcoal in a crystalline form; and that the valuable gem may be readily resolved by fire, into those aëriform matters which constitute alike the noxious exhalation of the Grotto del Cane, and impart a grateful taste to Champagne and Moselle.

Chemistry also teaches man that the sand on the sea-shore, when mixed with the calcined ashes of a sea-weed, and exposed to the intense heat of the furnace-fire, quits its pulverulent form, and assumes that of a transparent solid, of astonishing beauty and utility. It is employed by the astronomer to form lenses of prodigious power, by which, properly adjusted, he is enabled to watch the motions and penetrate the abysses of the starry heavens: without this interesting substance, many of the sublime truths of astronomy,—the researches concerning heat and light,-the natures of numberless aëriform bodies, would have remained unknown, nor could "the naturalist have investigated the forms and appearances of that wonderful part of the creation whose extreme minuteness eludes the observation of the unassisted eye." In place of the clumsy wooden cups and uncouth vessels of coarse earthenware, employed in domestic use by our forefathers, we range upon our tables crystal drinking-vessels, of the most elegant design and skilful workmanship; and spreading the same material into sheets of great size and regularity, we set it in the apertures of our dwellings, to exclude the rude winds, but to permit the cheering rays of light to enter; a luxury unknown even to the rich in former ages, but now enjoyed by every class, the most indigent not excepted. To a similar process we are indebted for all those beautiful and elegant services of porcelain which adorn our tables; all the brilliant and lovely colours with which it is tinted, are the products of the chemical laboratory, where they have been extracted from metallic bodies, by the torturing agency of acids and fire.

Chemistry presides over the production and permanence of all those beautifully vivid and varied colours which tint the fabrics of the loom, and points out to the manufacturer the method of simultaneously creating many together upon his goods, or of instantaneously destroying all, and leaving the surface of an exquisite whiteness. Our modern habits and fashions have rendered these arts of paramount importance; and, in con

junction with others, they contribute not only to the gorgeous splendour of the princely court, but to the neatness and decoration of the peasant's cottage.

Whatever researches are undertaken by the chemist, his grandest results are utility, and the application of scientific principles to the arts and manufactures. “The true end of all science is to enrich human life with useful arts and inventions." These are the words of the illustrious Lord Bacon; and they are worthy of record in letters of gold, in the laboratory of every experimenter. The vast and rapid advances which have of late years been made, not only in chemistry, but throughout the entire circle of science, may safely be referred to the steady pursuance of the plan of "inductive reasoning" laid down by this philosopher, in his Novum Organon. Previous to the appearance of this singularly acute and profound work, the state of philosophy was deplorable ; and he who could frame the most fanciful theory, and incomprehensible hypothesis, or mystify his doctrines to the highest degree, appears to have been regarded with the greatest veneration. Truth was either entirely sacrificed at the shrine of self-aggrandizement, or her fair proportions so distorted and mutilated, as to be almost undiscoverable. Experiment (saving alchymical experiment) was scarcely ever resorted to; indeed, the philosophers of that day deemed its practice far beneath their dignity; and held in sovereign contempt those who were the advocates for, or "makers of experiments," styling them "a tribe of idle curious people, whose philosophy consisted in making experiments on the gravity of air, the equilibrium of fluids, the magnet," &c. "A philosopher," said they," should go no further than the contemplation of things, leaving the execution thereof to another set of men; though he should have a certain theory thereof, in order to judge pertinently of them."

The true philosopher, however, at length discovered that the con-templation of things was not incompatible with practical execution, and that the "lover of wisdom" could suffer no real degradation in the eyes of his fellow-men, by resorting to manual labour, in order to verify the workings of his mind. The splendid series of discoveries that has been consequently made in all departments of knowledge, but especially in chemistry, has enabled man to work wonders upon matter, in all the various forms of it with which he is surrounded, causing them each in turn to minister to his wants or his luxuries, and thus triumphantly to assert the truth of the Baconian precept, that “ Experiment is the basis of philosophy," and that such "knowledge is," indeed, "power."

The safety-lamp and the steam-engine are magnificent examples of the application of refined principles of science to purposes of practical utility; and they constitute two of the brightest gems in the diadem of experimental philosophy. Nothing is now considered beneath the notice of the true experimentalist; and facts or observations the most simple, have given birth to discoveries and results of the greatest magnitude and importance.

In chemistry this is perpetually occurring; and with the view of showing how intimately its admirable laws and important principles are connected with arts and manufactures, and with various operations of constant occurrence in domestic life, it is intended that the present introductory paper shall be followed by a series, giving a familiar but a connected and strictly accurate view of the science and its applications.

THE GALLERY OF PRACTICAL SCIENCE.

No. II.

1. MANBY'S LECTURE ON SAVING LIVES FROM WRECKS.

2. AUTOMATIC SHIP AND SEA.

3. MAGNETIC NEEDLE.

MANBY'S LECTURE; Wednesday, 24th February, 2 P. M. CAPTAIN MANBY delivered, in the Long Room of the Gallery, a lecture on the most efficacious means of saving the lives of shipwrecked sailors, and illustrated his description by numerous models of the various apparatus invented by him; and which is happily, now, very extensively and successfully used in many instances on our own shores, and in several other parts of the world.

This veteran in the cause of humanity, after an application of nine and twenty years to the prosecution of his philanthropic labours, seems to have lost little of his energy. He gave, in a condensed form, the results of his long experience, and it appears that he can look back upon his past life and claim the singular and honourable distinction of having been the means of saving the lives of six hundred of his countrymen, and of one hundred of foreigners! Has he yet received ONE civic crown? He has latterly been pursuing his favourite object, that of rescuing his fellow-creatures from painful and horrible death, in other directions, and has now ready to present to the world, plans for the saving of drowning persons under whom ice may have broken; for the prevention of fires in buildings, and for the rescue of persons from houses, &c. in flames.

The profits which may arise from his publication, he proposes to devote to the construction of a complete apparatus, designed by him, for the assistance of persons immersed in water, in consequence of the giving way of ice beneath them, and which he is anxious may be ready before the ensuing winter, and thus prevent the possibility of the recurrence of the distressing events which happened on the Serpentine River last Christmas-day. He also proposes to subscribe five pounds in addition.

The Captain thought it his duty to make a statement, which, we submit, would become the Humane Society to notice, in order to remove even the shadow of a suspicion of any misapplication of the sacred funds intrusted to their charge. For ourselves we disclaim having the slightest, and are perfectly satisfied that there can be no real ground for any; but it is enough that some persons think otherwise, and that the statement has been publicly made. It is, that the late Dr. Fothergill left five hundred pounds to be applied by the Humane Society to the "prevention of shipwreck," and to "the preservation of shipwrecked mariners;" and that although the estimable devisor had been dead many years, not a solitary application of money to this object had yet been made by the Humane Society.

AUTOMATIC SHIP AND SEA.

IN our last Number we gave an account, in the "Standard Clock," of a combination of exquisite and carefully-constructed machinery, designed to attain an object of the highest importance, and certainly one of the most difficult accomplishment. The utility of such a machine may be estimated in a greater or less degree by every one, but its peculiar merits and construction can only be appreciated correctly by the highlyscientific few. In the present article we propose to address a much more numerous class than the latter, in which we particularly include our juvenile readers; we offer a subject, actuated by the same kind of agency, but having no pretension beyond that of being an agreeable object of observation, and which we intend to make instructive, by delineating and explaining the machinery through which its peculiar effects are produced.

The object we have selected for this purpose is one lately added to the collection in the Gallery-A SHIP AT SEA. To those of our readers who may not have seen this automaton*, we must premise that it is one of the most successful attempts at imitative motion ever accomplished. It is perfectly free from all those interrupted staccato effects which generally mar the finest productions in clock-work; and it most faithfully exhibits the easy, ever-varying, and ever-blending changes of position and surface, which a steady stiff breeze will produce on a flowing sea, and a vessel under full sail. It is surprising to see how accurately two of the most magnificent instances of nature and art are embodied, and their peculiar movements enacted on so small a stage-a field of ocean heaving with life, and a man-of-war floating, sailing, and even vibrating with the roll of the waves beneath her; enclosed by a glass-guard, and an oval of a few hands area.

The sympathy, if we may so term it, of the ship with the sea, is admirable; when she seems to overtake a wave, her bow slides up its side, and is projected into the air; as she rides on its breast, her stern also becomes elevated, and her deck is, for an instant, horizontal; and then, as she leaves it, her bow is depressed, and she sinks bodily down into the succeeding hollow. This last effect is so perfect, that a lady, visiting the gallery, was heard to exclaim to her companion, "Do come away; that subsidence is really so natural, that it brings all my recollections of sea-sickness about me.”

To give an idea of the actual size of our vessel, we may state that, from stem to stern, she measures five inches and a half, so that she appears to be not much larger than her portrait in the annexed diagram.

Though the effects are so perfect, yet the mechanism, it will be evident, is very simple. It is concealed in the model from the observer, by a membrane (v), which is attached to the hull, and thence extending to the borders of the machinery-chest, is there fastened. This membrane is very delicate in its texture, and extremely pliant; it is not strained tight, but, on the contrary, left very full; and its surface is painted to represent an agitated sea. In all the elevations and depressions of the vessel, this

* A machine that has the power of motion within itself.

membrane of course accompanies it; but to the spectator, the motions of the vessel seem to be the effect, and not the cause, of the waves.

In the diagram (fig. 1), one of the containing plates of the machinery is removed, to show the connexion of the parts. A spring contained in a barrel (a), communicates motion through a train of pinions and wheels (b, c, d), to two wheels (e, f), which have each the same number of teeth, and are geared together; on the axis of these wheels are cranks (m, k), which move two shafts (1, n), attached by centre-pins (o, p,) to the keel (q) of the vessel. To this keel is also attached, by a centre-pin (s), a lever (r), which, resting on a fulcrum (t), is continued beyond to any convenient length, and has, near its end, a moveable weight attached (u). One of the cranked wheels (f) is geared by a pinion and wheel (g, h) and an endless screw (i), with a fly (j), for regulating the velocity.

Supposing the lever (r) to be removed, the cranks and the shafts