DESCRIPTIVE ACCOUNT OF ALL THE

PATENTS ENROLLED BETWEEN 20TH DECEMBER, 1829, AND 20TH JANUARY, 1830.

Particularizing the Offices in which the Specifications may be inspected, with the Dates of Enrolment.

STEAM-ENGINE AND PROPELLING.-To Elijah Galloway, of King Street, Southwark, a patent for "certain improvements in steam-engines, and in machinery for propelling vessels, which improvements are applicable to other purposes," was granted on the 24 of July, 1829, and the specification was deposited in the Enrolment Office on the 2d of January, 1830.

The improvements in the steam-engine here contemplated, consist of arrangements, by which a continuous rotatory motion is obtained from the alternating circular motion of a piston or flap vibrating within a hollow cylinder on an axis coincident with the axis of the cylinder. The piston in this instance is a rectangular flap, whose length is equal to the interior length, and its breadth equal to the radius of the cylinder. Three sides of the piston are made to fit the interior of the cylinder steam tight, by metallic or other packing, and the fourth side is attached to an axis with which it vibrates, making about three-fourths of a revolution at each vibration. It is scarcely necessary to remark here, that the steam is admitted on the opposite sides of the piston alternately through the medium of a two-way cock, or shifting valve, acted upon by the motion of the apparatus.

The force of the steam thus exerted upon the piston is transmitted to a fly-wheel, and thence to any required purpose in the following manner :-To one end of the piston axis, which is passed through the end of the cylinder, is fixed a crank, which, by acting in a longitudinal slit in the middle of a lever moving on a fixed pivot at one end, alternately elevates and depresses the other, and thus, through the medium of a connecting rod, communicates motion to the fly-wheel.

This engine, it will be perceived, is of the kind usually denominated rotatory, and it is not free from an objection common to all engines of this description, the difficulty of obtaining an efficient and lasting packing for a rectangular piston, while it is subject to the inconvenience of nearly as much alternating motion as the common engine.

Mr. Galloway's proposed improvement in machinery for propelling vessels has for its object a remedy for the loss of power, 1ST FEBRUARY, 1830.

VOL. IV. NO. 79.

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and other inconveniences arising from the oblique position in which the float-boards of the common paddle-wheels enter and leave the water. This he proposes to effect by causing each float-board to turn, or rather vibrate on an axis at its edge next the centre of the paddle-wheel, through the medium of projecting levers firmly fixed to the float-boards at their axis of motion, and connecting rods proceeding from the extremities of these levers to the extremity of a fixed crank adjustable at a given distance from the centre of motion of the paddle-wheel, which consists of four radiating arms, connected at their extremities by strengthening braces.

The projecting levers or arms make with the float-boards angles of about 120 degrees, and thus the paddles or float-boards are made to enter and leave the water, deviating from the vertical only so much as is required to prevent the agitation of the water arising from the speed of the vessel.

The singular coincidence of Mr. Galloway's patent improvement in propelling apparatus, and Mr. King Williams's exhibition of a model of the same construction as his invention in the National Repository, we leave to these ingenious parties to explain.

PROPELLING.-To Jacob Perkins, of Fleet Street, London, engineer, a patent for "certain improvements in machinery for propelling steam vessels," was granted on the 2d of July, 1829, and the specification was deposited in the Enrolment Office on the 2d of January, 1830.

This patent, like the preceding, has for its object the saving of power and splashing of water; but the method here proposed is very different from that described by Mr. Galloway. Mr. Perkins places each of his paddles, consisting of a series of floatboards, on the extremity of a radiating arm, in such a position that its plane, if produced towards the centre of motion, would make with the axis of the paddle-wheel an angle of 45 degrees. The axes of the paddle-wheels are not carried across the vessel in the customary manner, but are carried in a direction sloping towards the stern, Plate XIV. figs. 1, 2, and they meet in a straight line drawn from stem to stern along the middle of the vessel, making with it an angle of 45 degrees, and with each other an angle of 90 degrees. On the extremities of the axis are fixed bevel wheels, which act upon each other, or are both acted upon by an intermediate bevel wheel in connexion with the steam-engine or first mover. Now, by this arrangement, the surface of each pad

dle is perpendicular to the side of the vessel, or to the line of motion when immersed in the water at its greatest depth, and parallel to the line of motion, when at its greatest elevation, and presenting an angle of about 45 degrees, in the horizontal position, whether in the act of ascending or descending, and from this angle it deviates but little when in the act of entering or leaving the water, as the patentee proposes to immerse the wheel to about one-fourth its diameter.

At Plate XIII. fig. 5, is a diagram representing the outline of a vessel with these paddles attached. a the boat; b b the paddle axles, to which an uniform motion is given by the engine through the medium of the bevel gear which connects them; c c are two of the paddles immersed in the water, and in the act of propelling; dd, e e, and ff, are those paddles which succeed. each other in the revolution. The oblique action of the blades of the paddles, as they perform their revolutions, will be more clearly understood by reference to fig. 5, wherein the paddles are marked by the same letters as in fig. 6, to which therefore the observations already made will apply.

By this method of causing the paddles to enter and leave the water, in an oblique position, it is presumed that the agitation will be very slight, and the consequent loss of power proportionally trifling: `and it will be readily admitted that paddle wheels of this construction have the important advantage of being equally simple, a circumstance which will render them equally durable with those of the ordinary construction.

But while these advantages are admitted, it must not be forgotten that a considerable portion of the power employed is entirely lost in consequence of the oblique position in which the wheels are made to revolve.

This obliquity of position, if carried to the extreme, and there can be no maximum of effect obtainable by limiting it to 45, or any other number of degrees, would entirely prevent the agitation of the water at the very moment when the motion of the wheels would entirely cease to have any effect in propelling the vessel.

CORN MILLS.-To John M'Curdy, of Great James-street, Bedford-row, London, a patent for "certain improvements in the method of constructing mills, and mill stones for grinding," was granted on November 2, 1829, and the specification was deposited in the Enrolment Office on the 2nd of January, 1830.

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