system is that its manner of loading, and small recoil, allow of casemates being of less depth, thereby saving expense of construction. About the year 1832 a small gun, having a leaden bullet of 107 grains, was tried at Turin. In this model the bore was pierced right through the piece, and the breech was crossed horizontally by a quadrilateral hole, where a coil was placed, to block up the bottom of the bore after the piece was loaded. This has been the basis of all subsequent inventions. The first experiment on a large scale was tried in Savoy on a six-pounder, which, after a few improvements, succeeded so well that a similar one was cast at the Acker foundry, in Sweden, by the Baron Wahrendorff. The Swedish government afterwards cast twenty-four-pounders for this purpose; and in 1842 they were tried at Woolwich. The object intended was to show how by this system, being applied to guns on board ship, the accidents which sometimes occur from the difficulties of running guns out and in would be obviated. Although the experiments proved successful, yet the still complicated manner of closing the breech would not allow of its being brought into general use. M. Gardner's model, although ingenious, by no means lessens this objection; the mass of mechanical force employed for this purpose being excessively cumbersome, and the length of the lever which he employed, if on the scale of a twenty-four-pounder, would be perplexing.

The improved gun-carriage, exhibited by Messrs. Ferguson, is well worthy of attention. It consists of a most ingenious application of the slide to common broadside carriages, including friction chocks, training chocks, and trucks of an improved form. These important improvements can be fitted to the broadside carriages now in use without occupying any more room on deck; nor would their application alter the general appearance or system of exercising the guns; while a saving of expense would be effected, both in time and labor, as compared with the working of ordinary carriages. The friction chocks act as a powerful check to the recoil, and also prevent the guns running out otherwise than required; these movements being under perfect control by one man, and capable of being regulated with the utmost nicety. Guns fitted with the im. proved carriage may be secured at sea by any of the usual methods, in addition to which they will have the powerful aid of the friction chocks to keep them in their places. In case of injury, all the parts are easily repaired; and should it be necessary to transport the guns on shore, or on board other vessels, the added improvements will in no way impede their usefulness as common carriages, and the additions may be removed in a few minutes, if required.

The howitzers and mortars of wrought iron, from Spain, indicated a certain class of artillerists who desire to introduce wrought-iron into the service for field guns. There are two qualities necessary for the soundness of every gun, which are tenacity and hardness of the metal; and the superiority of one piece over another (all their points being similar) is calculated by the quantity it bears to the other relative to these two propensities. A certain weight is also requisite to prevent too much recoil. Every species of wrought-iron presents a fibrous structure-the fibrous being more or less distinct and apparent according to the process made use of in the work. In iron beaten with the hammer, the grain or the fibres are not so casily discerned, and the bars have a more uni

form tenacity in the several directions. By comparing with one another the several processes by which iron is wrought, we come to this conclusion: that the fibres always form in the direction in which the iron lengthens. All that has been said with respect to iron is generally applicable to steel, except that the force or cohesion of steel far surpasses that of iron bronze; and iron castings, on the contrary, present a uniform force of cohesion in every direction-their structure consisting in an admission of crystallized grains, of which the crystals are often apparent to the naked eye. Although these wrought-iron guns present apparent advantages-amongst others, of having the direction of the fibre of the iron perpendicular to the axis of the gun, where the greatest strain from the power is exercised-yet their objections in real service are so great that their practicability cannot be admitted. It is difficult to bore them so accurately that no fissure should be made in the metal, which, on ramming down the powder, might cause ignition. They soon destroy the carriage by the suddenness and length of the recoil.

The oxidation of the bore will so enlarge it as to render it unserviceable; and not the least of these objections is the moral effect on the men from the fear of their bursting. If wrought-iron is objectionable in field guns, it is more so in those of large calibre. An almost insurmountable difficulty exists in welding the parts together perfectly, and an impossibility of ascertaining whether the welds are perfect; for when the boxes. are of small size, as in gun-barrels, the hammering compresses and reunites the particles, and corrects these defects; but in large masses the effects of the hammer do not reach the interior of the mass, which is consequently left open and spongy, although the metal on the surface, and to a slight depth, is compact and fibrous.

The shot and shells of cast steel from the Russian imperial works were fine-looking specimens of their projectiles. The hardness of their surface will be valuable in the field, by causing more dependence to be placed on the accuracy of windage.

From the United States three different kinds of articles in gunnery only were exhibited. These were the common army rifle, Colt's revolvers, and Maynard's primer. The first of these, manufactured by Robbins & Lawrence, of Windsor, Vermont, received much approbation for the excellent quality of their material, and the thoroughness and completeness of their workmanship. The second article mentioned, Colt's revolver, probably gained a firmer hold in the estimation of the best judges of fire-arms than any piece of gunnery which has been invented the last fifty years. Though it had been long in use with us, both for army and sporting purposes, it seems not to have been known in England. Meeting with doubts upon its first presentation at the Exhibition, it gradually gained its way into favor, until, before the close of the Crystal Palace, it was universally acknowledged to have achieved a success unequalled by a single invention from any part of the world. Hardly second to the revolver in the impression made upon the public mind was Maynard's primer. This most ingenious and effective piece of mechanism, the very simplicity of which is its greatest wonder, when applied to fire-arms of any model, increases their efficiency to a degree. which, to be fully realized, must be personally witnessed. Too late in its arrival at the Exhibition to be passed upon by the jury of awards, it received, nevertheless, from scientific men, army officers, and professed

sportsmen, a meed of approbation that far exceeded any renown it could have acquired from the "medal" or "mention" of excellence.

The detonating material of Maynard's primer is in the form of little lozenges, each about one-sixth of an inch wide and one-thirtieth of an inch thick. These lozenges are enclosed between two narrow strips of strong paper, cemented together and rendered water-proof and incombustible. The single strip thus made is a little less than one-fourth of an inch wide, and contains four of these lozenges (each of which is a charge) in every inch of its length; the charges forming projections of their own shape on one side, leaving considerable and equal spaces between them; the other side of the strip being one flat surface.

One of these strips, containing fifty (or more or less) charges, is coiled up and placed in a magazine in the lock, where, by opening a lid, it can be inspected readily, and from whence it is fed out by the action of the lock, one charge being moved forward each time the hammer is raised. When the hammer descends it cuts off and fires the charge fed out upon the nut (or nipple, if one be used) of the gun, thus igniting the powder of the cartridge in the barrel.

These primers are made by a very simple machine, (also invented by Dr. Maynard,) capable of making a million a day, at about one-tenth the cost of the percussion caps heretofore used in the United States army and navy.

CONCLUSION.

A comprehensive view of the vast collection of objects in the great Exhibition is the great desideratum with all those persons who have read only of its marvels. Such a view it is not easy to give. Every report which has ever issued from that great storehouse of industry, whether from the royal commissioners, the foreign commissioners, the juries, or the executive committee, has dealt of details. It has almost necessarily done so, because through details alone could the mind create any picture of the vast edifice, and its contents, which should at all resemble the original. And yet a comprehensive view of the whole-so that, when the disposition and arrangement of the building have been mastered, a just conception may be formed of the whole display, the characteristic features of each part be distinguished, and definite ideas of the industrial attributes developed be stored in the mind-is what is most needed.

The industries of nearly all the nations of the globe were presented in Hyde Park. In those industries the national individuality was preserved. They became the most faithful mirror, in fact, of national character which could be exhibited. Other pictures may deceive, but the picture which the industrial products of a people present must be true. The course of events, guided as it is by a higher power than man's, does not always illustrate the moral and social attributes of communities. Not so the fruits of labor-the quality and description of material which engross the toil, supply the demand, and engage the tastes and predilections of a people. These tell their tale as faithfully as the actions of an individual indicate his nature, and by them, rightly considered, the condition and progress of a community may be correctly judged.

The form of the Crystal Palace has been made familiar, by innumerable pictures, to the whole world. In some respects it resembled a cathe

dral, its long avenues, stretching from east to west, being intersected midway by a transept. An equal division of space thus resulted, which was turned to account in the most appropriate manner. The western half was occupied by the industrial products of the British empire; the eastern by those from other countries. The question of precedence, not as between Great Britain and the world, but between all foreign rivals, was settled by a geographical solution. The transept was the equator. India, on the British side; China, Tunis, the Brazils, Persia, Arabia, Turkey, and Egypt, on the foreign side, were grouped around it as the torrid zone.

This geographical plan was not, and indeed could not be carried out through the whole building; but it extended far enough to destroy all ideas of preference as to locality, and all feelings of jealousy arising therefrom. It harmonized, also, admirably with the character of the structure, and gave a symmetry and equipoise to the whole which would not otherwise have been attained.

As Great Britain occupied the greatest space-a space equal to all the rest of the world-she certainly deserves the first notice. Crossing the transept, the first compartments westward were occupied by the products of the British colonies. India-with its pottery, its inlaid ivory, its renowned textile fabric, its jewels and gold, surpassing the most finished productions of any European nation-contrasted strangely with India as the contributor of the rudest furniture, the most awkward machinery, the most uncouth household implements, and the most fitless mechanical tools of any country on the globe. And yet nothing could more correctly represent India as she is-uniting the highest skill with the most brutal ignorance, princely wealth with abject poverty, and luxury beyond description with want that seeks no higher end than the sustenance of a day. The Australian possessions, the Canadas, Nova Scotia, New Zealand, the British West Indies, the Cape of Good Hope, Malta, western Africa, the Channel islands, and all other parts of the world where the cross of St. George has been planted, were each represented by itself in its own peculiar products. In some were seen the evidences of barbaric pomp, belonging to the traditions of the past; in others the rudeness in design and material of all the useful arts; in others yet the trophies of ancient civilization and refinement, marvellously brought down to our own time; the fruits of labor upon the virgin soils of Australia and the Canadas, sent to be consumed in the mother country; the mineral, vegetable, and animal treasures, sought out by commerce and made valuable by manufactures; and the raw produce in various conditions, indicative of the struggle of infant communities towards a larger industrial development.

The colonies of Great Britain occupied, nevertheless, but a fractional part of her immense space in the Crystal Palace. It was from the United Kingdom that the great mass of her productions came. The comparative ease, freedom from expense, and direct benefit to be gained, which the British contributors enjoyed, furnished one great reason for the full representation of the industrial products of the country. But, with all these advantages, no person could witness the extent, variety, and excellence of the proceeds of British labor with which nearly onehalf of the immense fabric was crowded, and at the same time remember that each one of these myriads of articles was but a sample of vast pro

ducts daily issuing from loom, and furnace, and workshop, to fill the markets of the whole world, without astonishment and admiration. Her raw produce, filling one immense compartment, half the length of the whole building; her mining, quarrying, metallurgic, and mineral products, occupying the extreme south; her chemical and pharmaceutical products and processes-substances used as food, and vegetable, and animal substances used in manufactures-stored in the galleries; her pleasure carriages and railway and naval mechanism, arranged along the north; her civil and military enginery, on the west; her agricultural implements, occupying an immense ground area parallel with her minerals; her philosophical, musical, surgical, and horological instruments, and the processes depending upon their use, handsomely arranged in the galleries near the nave; her display of manufacturing products, comprising nineteen sections, arranged on either side of the central avenue above and below-cotton woven fabrics, fabrics woven of mixed materials, leather, furniture, hardware, cutlery, furs, and paper, occupying principally positions on the ground floor; and silks, velvets, shawls, carpets, floor-cloths, clothing, jewelry, glass, ceramic manufactures, and earthenwares placed in the galleries of the nave; he fine arts, crowding the sculpture court, and scattered throughout the building; and her manufacturing machines and tools moved by steam, plying their multiplex labor in one immense and separate compartment-showed what must be that vast and complicated system which supplies the materials to feed her swarming millions, which maintains her commercial credit, and enables her to pay the interest of a debt which would overwhelm most nations of the world.

The genius of Great Britain is mechanism. More than in any country on the globe, mechanism is there extending its dominion over the whole empire of labor. In textile fabrics, in fashioning iron like wood to the most exact proportions, in working the printing press and navigating the ocean, in all agricultural pursuits everywhere, in everything lightening the burden of toil and rescuing human life from dangerous pursuits, nechanism reigns supreme. Beyond this the genius of Great Britain has not gone. Ornament in all her productions is inseparably wedded to usefulness. The creation of the beautiful with her artisans rests only in the adaptability of mechanism. It is said that a better and purer style of national industry is beginning to be observable in England; but however this may be, her best productions, when placed beside similar productions from the continent, show violation of harmony in color and design, and evidences of neglected taste, to the most casual observer. But in mechanism, in its highest and noblest ends, in its tendencies to relieve labor of its drudgery, and to delegate to iron, to steam, and to other powers of the inanimate world the burden of toil, Great Britain must be acknowledged to be in advance of all the world.

Crossing the transept, in the centre of which the crystal fountain glit. tered in light, China, Tunis, Egypt, and central and southern American tropical countries, first spread out before the spectator their various productions. The collection of Chinese manufactures bore that peculiar impress of which no article from the "flowery land" is ever divested. The porcelain from the great works of the Pozang Lake, the chemical preparations, recalling the historical fact of the early development of chemical knowledge among its inhabitants, the edible birds' nests, the