turu, and the water to flow from a pipe 7, into the hollow platen, when, by the pressure obtained from a column of water of about ten feet high, the required force is exerted to give the impression.

This being done, the rounce or wheel ƒ, is now to be turned the reverse way, when the power of a helical spring on the oblique rod or bar k, will bring the rod back to its former situation, causing the rack to turn the cock i, and to close the water way from the pipe 1, and open a way to the discharge pipe m, by which the water runs out of the hollow platen; and slight springs carry up the flexible plate into the platen so as to set the table with the form and the printed sheet of paper free. The table is thus run back into its former position, the printed paper is removed, and the form again inked for another impression.

As the table recedes, a disc on the axle of the wheel g, acts upon a tooth at the end of a levern, raising that end of the lever. The other end of this lever is connected to the register pins, and draws them down away from the timpan; but when a notch in the edge of the disc comes round so as to allow the tooth at the end of the lever n, to fall into it, then the register pins are forced up ready to place the sheet of paper to be printed.

The Patentee says in conclusion, "I do not intend to claim as my invention any of the parts of the machine described, nor do I mean to limit myself to the employment of any particular materials for constructing it, but I do claim the use and application of a flexible or elastic platen, in manner herein before described, the application of pressure thereto in printing presses, copying presses, &c. &c. by means of a liquid or aeriformed fluid, in manner herein also described; and the arrange

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ment of the machinery or parts of the said presses for the purpose of applying such pressure of a liquid or aeriformed fluid to such flexible or elastic platen.-[Inrolled in the Inrolment Office, March, 1835.]

TO WILLIAM BRIDGES ADAMS, of Long Acre, in the parish of St. Martin-in-the-Fields, in the county of Middlesex, coach-maker, for his invention of an improved construction of wheels for all kinds of carriages, in which springs are commonly used.-[Sealed 13th March, 1835.]

THE Patentee has fallen into the same error which has misled several patentees before him, conceiving that the draft of a carriage will be facilitated by giving elasticity to the spokes of its wheels, but finding that all previous attempts of this kind have failed, conceives that the fault lies in the form of the springs, not in the principle.

After, therefore, expatiating upon the defects of radial spokes, as well as those made in curved and elliptical forms, suggests, as the real thing necessary, that the spokes should be made of circular flexible hoops, observing that the efficient spring wheel should be so made that the elasticity should be alike in all parts of the circumference.

It is not necessary that we should follow the Patentee in all his reasonings, but merely explain the construction which he has proposed to effect his object; viz. by so forming his wheels as to afford that ease and gentleness of action in the body of the carriage, for which springs in general are applied to carriages.

Plate VIII., fig. 8, represents an elevation of the improved wheel; a, a, a, is the felloe or rim of the wheel, made by any required number of curved pieces of wood, accurately fitted together as the staves of a barrel. These are placed round a ring of steel as an inner tire, and are bound tight on the outer periphery by the ordinary tire or ring of iron, placed on to the felloe in a heated state, and shrunk thereon to keep the whole tight. To the inner part of this wheel four steel hoops b, b, b, b, are attached by bolts at equal distances apart; and the opposite parts of these hoops are made fast to the central box or nave, formed of iron plates in the shape of Maltese crosses, and filled up by wood. Through the centre of this box the axle of the carriage is to pass, and be fitted and secured in any of the most improved modes.

A wheel so constructed, it is presumed, will possess a slight degree of elasticity, that is sufficient to give way to any small obstruction on the road which it may pass over.

It is suggested that this construction of wheel will be particularly desirable on railways, as its elastic property will enable it to neutralize the effects of passing over ill-formed joints in the road; it is even considered that should the wheel by accident pass off the rail, its elasticity will have a tendency to throw it up on to the rail again.-[Inrolled in the Petty Bag Office, May, 1835.]

SCIENTIFIC COMMUNICATION.

ON THE TEMPORARY SECURITY OF FRACTURED PADDLE-WHEELS.

To the Editor of the London Journal of Arts.

SIR, Many plans for the temporary security of various damaged parts of sailing vessels, such as sprung or fractured masts, spars, bowsprits, temporary rudders, &c., have, from time to time, been given to the public through your, and other scientific journals, by those to whom such accidents have happened, for the benefit of their brother navigators; and, in my opinion, it is the duty of every one to whom such misfortunes occur, to make known the means he has found of overcoming the difficulty by temporarily repairing the damage. There is many a man who, when sitting quietly in his cabin or parlour, can think of different ways of getting out of trouble; but the desirable thing is to have some scheme, and that an effectual one, at hand the moment an accident or breakage occurs, when all the commander's wits are wanted to attend to his vessel, to see that all hands are at their duty, in order not only to secure his ship, but to prevent further damage. At this time he most wants his inventive genius assisted; but his mind is too much engaged with the passing events to allow of his coolly inventing an eligible scheme, or at least the best possible expedient, which might at other times occur to him, to overcome his difficulty.

The captains and masters of sailing vessels have, as before stated, the advantage of the various suggestions and plans of their brother commanders, and which, I have no doubt, have been the means of saving many a valuable ship or cargo; but as yet, the marine engineer has not this advantage regarding the temporary security of any fractured or damaged parts of steam vessels, although the machinery of a steamer is as liable to accident as any part of a sailing vessel, and is, in truth, much more essential to her going. All machinery is liable to derangement; and as speedy reparation is most desirable; it, in my opinion, becomes the duty of every engineer who successfully overcomes for the time any breakage or

damage of an essential part of his engine, boilers, or paddles, to give the plan by which he has succeeded to the public, for their benefit when placed in similar difficulties.

It is in the hope of assisting a brother engineer at such a juncture, that I am induced to offer to your valuable pages the means I employed at the moment, when at sea, to temporarily repair a fractured paddle-wheel belonging to the Honourable the Trinity House vessel, the VESTAL, and which I found to answer well, and to last sound, not only during that voyage, but until we could conveniently run into port and repair in a workman-like manner.

The accident happened in one of our voyages round England and Scotland, and occurred to the starboard paddle-wheel, by a fracture through three of the cast-iron arms of the wheel near the boss. The accompanying sketch will fully explain the means employed to repair the damage.

Plate VIII., fig. 9, is a front elevation of the wheel; fig. 10, a side view, partly in section; a, is the engine shaft, b, the paddlewheel, c, the boss, d, d, d, the points of fracture of the arms.

It being an object to effect such a secure splicing as would enable the ship to prosecute her voyage instanter, and to avoid the probability of weakening the boss or the arms, by drilling holes therein, I hit upon the expedient of having a wrought-iron ring e, e, hastily forged for the porpose, and indented to catch each feather or rib of the arms of the wheel (seen best in fig. 10). This I immediately had secured to the several arms by lashing, as at f; I then applied a piece of timber g, g, athwart the whole, well lashed securely with chocks h, h, h, in order to equalise the strain of torsion throughout. The whole was fixed in four hours, and continued firm during this voyage in some heavy weather, and was used subsequently until the service of the ship conveniently admitted a more substantial repair.

Your readers may perhaps smile at my using the lashing instead of the more engineer-like mode of screw-nuts and bolts: but, in the first place, I did not want to weaken the cast-iron by drilling holes therein; and, secondly the time taken up by the lashing was much less than would have been occupied in drilling holes and