These trusses are placed to cross each other in a reverse diagonal direction, so as to resist either a tensional or compressive strain; they are made of 5 × 2 flat iron, are securely riveted above to every second or fourth upper deck-beam, and below, a butt on, and are secured to the upper side of the keelson. They are riveted together at their points of intersection, and where they cross the line of the old beams, a double central back-to-back 7×6 angle-iron clamp is riveted to every truss and beam. If desired, a similar angle-iron clamp may be riveted along at the junction of their upper extremities with deck beams.

The angle of these stanchions is about 60°, that being found best suited to the convenience of the hatch arrangement. The hatchways and masts can easily be left clear.

It is submitted, these stanchions form a central range of diagonal trussing at a part of a vessel requiring support, and which hitherto has not had such; they will be of great service in connecting together two strong frameworks, namely a vessel's bottom, and her upper deck platform. The writer also places the diagonal stanchion in athwartship direction; this he has found reduces vibration in steamers, besides clearing the screw-shaft. On these principles of construction, the writer's firm have nearly completed at Glasgow a 900-ton iron Indiaman, named 'The R. Mackenzie;' and he is glad to state that the result of such practice has more than realized the expectation formed from the theory; and respecting the element of expense, he finds that such a vessel costs £2000 less than a Thames or Mersey-built timber ship of the same size and class.

Plate Butt Frames.-In an iron vessel plated in the common manner, the writer uses butt-frames. In the place of the usual mode of securing the vertical joints of the external plating on an iron internal strop between the frames, they are secured upon a frame in the following manner. There is bent round the exterior of every alternate angle-iron frame, a long continuous plate of some breadth and thickness, as the ordinary butt-strop; this plate is punched before being fixed to the frame; the plate-butts or vertical joints are then arranged to be riveted only on this continuous butt-frame.

If longer outside plating be desired, every third frame may be constructed as a butt-frame.

If preferred, the continuous butt-strop may be placed between the frames, in one length, from keel to gunwale.

By either of these modes of securing the butts of common plates, no short buttstrops are required, and it is evident that a vessel having her butts or vertical joints so secured, is greatly increased in point of strength, and that there is little or no liability to break asunder at those points.

Ceiling. For the purpose of increasing the strength of iron vessels, the ceiling from the bilge keelson up to the gunwale is made of angle-iron or flat iron in one length placed diagonally and from 12 in. to 10 ft. apart, tailing from the centre of the vessel to the extremities. The port side of a ship being reverse to the starboard side, these diagonal ceiling bars are riveted to the reverse angle-iron of every frame, and their extremities secured to the gunwale angle-iron and bilge keelson.

These iron ceiling side trusses, in conjunction with my centrai range of stanchion trussing, yield great strength without occupying space, and both can be adopted with advantage in timber vessels and in battle-ships. If preferred, these diagonal ceiling bars may be of wood in iron vessels.

Iron Masts. The writer plates iron masts and spars diagonally from top to bottom, the plates winding round the entire length and riveted together. He also forms an iron mast of diagonal spiral lattice-work riveted together at their points of intersection.

If desired, such a mast may be stayed transversely in its interior throughout. The writer also fixes winches to iron masts, with their spindles through the sides of the mast, the aperture required for such spindles being compensated by an internal doubling plate.

War Ships.-Between the seams of the external planks of wood battle-ships exposed to shot, the writer inserts iron or steel plates, in thickness from 1 to 2 inches, and in breadth the entire thickness of the planks to which they are secured; these being in long lengths, are bolted vertically to the planks above and below them, and

besides increasing the strength of the vessel, will form a resistance to shot or shell: they may be placed from 6 or 8 inches asunder.

In wood battle-ships, he also fastens along the interior sides of their gun decks, vertical iron plates, from 1 to 2 inches thick, close secured and bolted through the n side. Such are for the purpose of resisting the shot after it has spent its force in penetrating the external wood side.

For the same purpose, he places fore and aft along the interior of the gun decks of wood battle-ships, angled metal shields, the apex of each being in the centre line of the gun ports, and bolted there through the side of the ship: where the upper and lower edges of these shield plates join the beams above and below, they are strongly bolted to the beams and to each other.

In an iron battle-ship or ram, he builds the side of the hull above water and plates it with 2 or 24-inch thick iron or steel. Outside of this he timbers, planks, fastens, and caulks the wood side of a battle-ship, not for the purpose of strength, but for a resisting medium, in which a common ball may spend its force before coming into contact with the internal angle-plated shields, which it is submitted will then turn aside the ball from penetrating into the interior.

These angled shields answer also for beam knees, the weight and cost of which may be dispensed with.

It is submitted, that owing to such angled shields, the reduced thickness of shield plates protected by the timber side, the diagonal arrangements of four tiers of beams, and the central diagonal trussings, an iron battle ram so constructed would have less displacement, greater strength, more buoyancy, greater speed, and be more creditable to the engineering science of this country than those now building at an expense of 1 million, the designs of which were not thrown open to public competition, although the Exhibition building, St. George's Hall, and some of the first engineering structures in England, are the result of such a course.

A Novel Means to lessen the frightful Loss of Life round our exposed Coasts by rendering the Element itself an Inert Barrier against the Power of the Sea; also a Permanent Deep-water Harbour of Refuge by Artificial Bars. By Admiral TAYLOR.

On Street Railways as used in the United States, illustrated by a Model of a Tramway and Car, or Omnibus capable of conveying sixty persons. By G. F. TRAIN, of Boston, U.S.A.

In America such a car is drawn by a pair of horses. The tramway is laid in the centre of the street, and the rail is so shallow that it offers no obstruction whatever to carriages crossing it. In wide streets two such tracks are laid down, one for the going and the other for the returning traffic. Mr. T. stated that in the cities of America the system was in constant use, and was now an absolute necessity there. He saw no difficulty in carrying out the system in our English towns or in London. Where there were inclines, an extra horse would be used; and where a street was not wide enough for two tracks, he would put down a single track there, and bring the traffic back by a line laid in a parallel street. He had received a concession to bring out his system in Birkenhead, and he hoped by September to be able to show it in operation there. All he required was leave from the authorities in any town to lay down his trams and run his carriages.

On a Mode of covering Wires with India-rubber.

By Messrs. WERNER and C. W. SIEMENS.

The authors exhibited a very ingenious machine for accomplishing this object. These gentlemen use no solvent or heat whatever, but take advantage of the property which india-rubber possesses of forming a perfect junction when newly-cut surfaces are brought together under pressure. The core or wire, with the ribbon of rubber applied to it longitudinally, is pushed into an orifice, which serves as a guide to carry them into the machine, so that the superfluous rubber is cut off by what may be termed a revolving pair of scissors, formed by a disc of steel with a sharp edge revolving excentrically against a stationary plate, and immediately, by

means of two grooved wheels, the edges are pressed together, and thus the wire becomes encased in a perfect tube of india-rubber. As many additional tubes as may be desired can be then put on. The machine is also applicable to the coating of wires with what is known as Wray's Compound, with vulcanized Indiarubber and other compound substances containing India-rubber.

APPENDIX.

PHYSIOLOGY.

On the Deglutition of Alimentary Fluids.

By Professor J. H. CORBETT, M.D.

In this paper the author describes two distinct forms of deglutition; that while the alimentary bolus is propelled with rapidity over the epiglottis, fluids can flow in two streams, one at each side of the epiglottis and of the aryteno-epiglottic folds, without the danger incidental to its passage over the central aperture of the larynx. He believes that such occurs in the newly-born infant and mammal during suction; it can take place in the sipping of fluids, swallowing of the saliva, and even during drinking in a continuous draught. Ordinary drinking is accomplished by gentle muscular movements, which should not be confounded with the gulping of fluids, In gulping, the fluid is rapidly and forcibly propelled backwards through the isthmus of the fauces, each gulp requiring a separate act of deglutition; such act much resembles the deglutition of solids. The author contends that when the infant or mammal seizing and retaining the nipple, sucks in the fluid in an almost continuous stream, the process of respiration is not totally interrupted, as should occur if the fluid absolutely passed in the middle line over the epiglottis; it is argued that the salivary secretion is swallowed safely during sleep; fluid carefully introduced into the mouth of persons in a state of insensibility, passes into the pharynx; fluid poured gently into the mouth of a patient whose head rests upon one side, flows backwards by a gentle act of deglutition, which is chiefly performed in this instance by the muscles of the corresponding side; fluids cannot be shaped like solid food into a definite form; alimentary drinks must be subject, in their course, to the laws which regulate the passage of fluids in other cases; the root of the tongue being narrow and the organ convex on its upper surface, fluids must naturally have a tendency to flow from the middle line to either side; during the mastication of solid aliment, the juices expressed by the action of the teeth and pressure of the tongue, rapidly escape backwards, so that the bulk of the mass is considerably diminished before the deglutition of the solid part is attempted; during inflammatory affections of the tonsillitic glands, the swallowing of fluids is attended with difficulty, while a moderately sized portion of solid aliment, which proceeds in the middle line, may be transmitted with comparative facility; when a single gland is much inflamed, deglutition is chiefly performed at the opposite side.

In experiments made by the author on the dead body, fluid poured upon the dorsum of the tongue passes backwards into the pharynx in two streams, through the grooved channels situated at each side of the epiglottis and aryteno-epiglottic folds. From all these considerations, it is inferred that in the living body, during the deglutition of fluids, the uvula falls forward upon the tongue in front of the epiglottis; thus both uvula and epiglottis afford protection to the respiratory apparatus. The fluid is divided by the uvula into two currents, which descend at each side of the root of the tongue, under the half arches of the palate, as water flows under the arches of a bridge; and such is the principal use of the uvula. The anatomical arrangements in the human body are perfectly adequate for the transmission of fluid in this safe manner. The anatomy of the porpoise, in which the larynx rises for several inches above the level of the tongue, affords a strong confirmation of this view, which is further sustained by instances in which the epiglottis has been destroyed, wounds of the throat, &c. The distinctness of the two forms of deglutition is also indicated by the fact that the mouth may be filled with food, and yet drink can be swallowed without displacement of the solid aliment; the newly-born infant can perform suction in a perfect manner; on the other hand, the power of swallowing solid food is gradually acquired, and the organs of deglutition are trained by successive steps to the safe performance of this process.

INDEX I.

REPORTS ON THE STATE OF SCIENCE.