same, and at the bottom of each are attached square blades, or fans, which are made in such a manner as to feather in the direction required. The upper parts of the shafts are cranks, which are in the body of the boat; motion is given to these cranks by steam; they work alternately, and would, it is thought, supersede the screw for speed. The reversing gear is well managed; but would appear to require some further improvement, owing to a tendency to get out of order.

Lieutenant Jones exhibited a propeller of quite an original description, which is placed in the centre of the vessel; the propellers, three in number, are made in the shape of spades, the handles being fixed to cranks, of which there are six, three in the upper shaft, or beam, and the same on the other, to the upper, only placed some few feet below it; the shafts, or beams, are fixed in the same manner as in the paddle-wheel; motion given to the cranks, and the propellers follow each other, going at the same speed as the cranks.

In Mr. Ruthven's model, when the deck is removed, there are seen apertures covered by a kind of flooring, which forms a case for the water which the apertures let in; this conducts the water to a well in the centre of the boat, in which works a wheel similar to a paddle wheel, only placed horizontally. To each side of the well is attached a pipe, extending to the side of the vessel, where it is connected with a movable nozzle. The engine power is applied to the axis of the wheel in the well, which, turning round, discharges the water through the nozzles, and propels the boat. If required to go astern, the mouth of the nozzle is turned towards the bow of the boat; if to stop, it is placed perpendic ularly downwards, and consequently will not exert any force either way. The faster the vessel goes, the more water comes in through the nozzles.

Of pleasure boats there was a large show, but not a very great variety. Mr. W. Biffen, of London, displayed a model boat, calculated to change into a four or eight-oars, at pleasure, by merely taking out some of the parts, thereby making one boat as good as two. When not in use, it can be packed so as to occupy less space than a single boat on the old principle.

A model of an outrigged sculling boat, sent by Noulton & Wyld, is very extraordinary, as the body of the vessel is composed of one single plank from stem to stern, without a joint or reel.

The Typhoductor, or Storm Pointer.

Colonel Lloyd, one of the special commissioners of the Exhibition, exhibited a very remarkable instrument, called a typhoductor, or stormpointer an instrument for obtaining by inspection the bearing and relative position of a revolving storm or hurricane. It is now a well ascertained fact, that great storms have a rotary motion, like a whirlwind. The theory commonly called the "law of storms," as made known in several publications by persons of eminence, has been established from thousands of well authenticated observations in different parts of the world, and extending over a period of several years. It proves that during a gale of wind, particularly near to the tropics, the wind blows with the greatest fury round a common centre; at this centre there is little or no wind, even a perfect calm; but there is generally a terrific and confused

sea.

The most violent and dangerous parts of these revolving gales are

somewhere near this central calm, the wind there blowing the most fiercely, acquiring, it is stated, a velocity of even a hundred miles an hour. These storms sweep both land and sea in certain parts of the globe; their track and direction are pretty well known, and they travel bodily from their place of origin to their destination at variable speedssometimes at not more than four to six miles per hour; sometimes, but seldom, at that of 20 to 30 miles per hour, although the wind within their range is blowing round with the fury just mentioned.

If a ship unhappily becomes entangled within the range of these terrible gales, she is in great peril. Many have foundered, and others have pursued their fearful course round and round until they have been reduced to helpless wrecks, dismasted and water-logged. In the northern hemisphere these winds blow round the compass from east, by north to west, or the contrary way to the hands of a watch; whereas in a southern hemisphere it is just the reverse, blowing round as the hands of a watch would go.

This principle must always be borne in mind as the very foundation of all the information to be sought hereafter. On these most valuable data, instructions have been drawn up by Colonel Reed, and others, how to ascertain the relative position of a gale, so as to know whether it is approaching to or going from a ship, travelling by its side, or crossing its path.

The object of Colonel Lloyd's ingenious instrument is, by graphic illustration, to show that when the wind blows from a particular point of the compass, you can only be in one relative position in regard to the centre of the whirl storm, so that either the storm is approaching the ship or the ship approaching the storm, and first, of course, encountering the outer edge. As a consequence of the law of rotation, the wind, supposing the whirl to be circular, must blow at a tangent, or right angles to the point of the compass where the ship or observer may be, but under diametrically opposite conditions, as far as regards the two hemispheres. Thus, in a northern hemisphere, if the wind blows east, the centre of the storm must be due south of the observer; blowing north, the vortex east; coming from the west, the centre of the gale is north; and, lastly, with the wind south, the gale is due west. Of course, in the intermediate points of the compass, the bearings are likewise different.

In a southern latitude the whirl-storm blows round just the contrary way. With an east wind the storm centre bears north; with a north wind, west; with a west wind, south; and with a south wind, east. Bearing in mind these facts, and with sea-room, it is easy not only to avoid hurricanes, but to make them subservient, in many cases, to the ship's ultimate course.

There was a formidable display of guns and weapons of every description in this section. In the English department some small models of artillery, amongst which those of Captain Tylden, were remarkable for their work and finish. Of the system of loading large guns at the breech, there is but one specimen, by Mr. Gardner, of Lambeth. Although this system is of the greatest antiquity, the amount of initial velocity lost by an imperfect closing of the breech caused it to be discontinued; but the introduction lately of long ranges, and an increased accuracy of fire from greater perfection in the guns, have again led attention to be directed to the subject. The advantage possessed by this

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 improved 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 easily 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

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 characterwhich could be exhibited. Other pictures may deceive, but the picture which the industrial products of a people present must be true. 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