case is made in the form of a parallelopipedon, the ends being square, and each of the sides a parallelogram, whose length and breadth are to each other as five is to one. One side of the trough constitutes

a lid, which is removed to introduce the flour and water, and the trough is divided into as many cells as there are balls introduced. The patentee states, that, by the rotation of this trough, the dough and balls are elevated together, and, by their falling down, the dough will be subjected to beating, similar to the operations of the baker's hands.

In the third method the dough-trough is similar to that used in the first; but, instead of the revolving cylinder, a revolving agitator is employed, consisting of a series of rings angularly attached to an axis extending the whole length of the trough.

The revolving apparatus in all three methods are put in motion by a train of wheels, actuated by the power of a man, or other first mover, according to the quantity of work to be done at one operation.

MUSICAL INSTRUMENTS.-To Charles Wheatstone, of 436, Strand, London, musical instrument maker, a patent for "certain improvements in the construction of wind musical instruments: was granted on the 19th June, and the specification was deposited in the Enrolment Office on the 19th December last.

About two years ago a small musical instrument was brought from the continent to this country, and distinguished by the name of the German Æolian-harp. It consists of a thin metalic plate, with a series of rectangular holes about three-quarters of an inch long, and the eighth of an inch wide. Upon this plate a series of tongues are screwed or riveted, made to play loosely in the apertures in the first plate, and filed thin, according to the tone intended to be produced. These thin tongues being firmly fixed at one end, and made to play in the apertures, are put into vibration by forcing wind through them by which tones of great strength and variety are produced.

Now, upon this principle Mr. Wheatstone has founded his improvements in musical instruments, for which he has obtained a patent. His instrument consists of an air receiver, furnished with a mouth-piece to fill it with air from the lungs, and as many of the apertures and vibrating tongues as there are intended notes on the instrument. On each side of the instrument are placed short projecting finger-knobs, by which the air is admitted at pleasure to any of the notes of the instrument. The keys, or finger-knobs, are arranged, in a kind of double row on each side, so that the finger may be applied to one or more at the same time, and the notes which constitute a chord are placed adjacent, so that the application

of the finger to two of them at the same time shall not produce disagreeable sounds.

Mr. Wheatstone also includes in his patent an improvement on the small instrument known by the name of the Chinese organ, which improvment consists in an arrangement of the pipes, by which the fingers can more readily reach and stop or open them while playing. He places the tubes in a circular order in the lower extremity of the mouth-piece, with the sound apertures distribnted according to the position of the fingers when the hands encompass the instrument.

MUSICAL INSTRUMENTS.-To Francis Day, of the Poultry, London, optician, and August Münch, of the same place, mechanic, a patent for certain improvements in musical instruments, partly communicated by a foreigner," was granted on the 19th June, and the specification was deposited in the Enrolment Office on the 19th December 1829.

These patentees, like the last, have taken for the foundation of their improvements the German Æolian-harp, but have produced an instrument of much greater power and utility, This instrument is furnished with keys precisely similar to those of a piano-forte; the air is supplied to the receiver by a pair of organ-bellows, actuated by the foot; and the tones produced by this arrangement of parts are exceedingly melodious and very powerful. The system of levers, by which the notes are opened by the operation of the player on the finger-keys, can easily be imagined, as they are not unlike those of a piano-forte; but there is one addition which we must not omit to mention, as it gives a peculiarity to the music produced by this instrument. The addition which we allude to is the application of a small spiral spring under each key, by which more powerful notes may be produced, simply by the application of greater pressure on the keys, and thus the player can regulate the strength of his music at pleasure.

NEW AIR ENGINE.

THE following sketch of an Air Engine for obtaining the advantages of all the expansive force of heated air, as well as the force arising from the semi-explosions of the inflammable gas evolved from the fuel, is extracted from Dr. Arnott's Elements of Physics, Vol. II., Part I., treating of heat and light, just published.

If, says the designer of this ingenious apparatus, we suppose a fire a (fig. 4, Pl. xii.) to be placed in a grate near the bottom of a close cylinder d a, and the cylinder to be full of fresh air recently

admitted, and if we then suppose the loose piston g d to be pulled upwards, it is evident that all the air in the cylinder above d will be made to pass by the tube e through the fire, and will receive an increased elasticity tending to the expansion or increase of volume, which the fire is capable of giving it. If there were only the single close vessel'd a, the expansion might be so strong as to burst it; but if another vessel b c of equal size were provided, communicating with the first through the passage b, and containing a close-fitting piston cf, like that of a steam engine, the expansion of the air would act to lift the said piston, and by means of it might work water pumps, or do any other service which a steam engine can perform. At the end of the lifting stroke of the piston fc, it might be made to open an escape-valve for the hot air, placed in any convenient part of the apparatus, and to cause the descent of the blowing piston d to expel this, while a new supply of air would enter by another valve into the cylinder above d. The engine would then be ready to repeal its stroke as before, and the working would be continued as in a steam engine.

PATENT APPARATUS FOR MEASURING AND REGISTERING THE QUANTITY, &c. OF FLUIDS IN TRANSIT. By Mr. BRUNTON, of Leadenhall-Street, London, 1829.

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I MEASURE and register certain fluids in transit by passing them through a cylinder with a piston and rod, nozzle and valve, or cock, in all respects like those of a steam engine, excepting that I prefer to pack the piston with leather, when the fluid to be measured does not exceed 80 degrees of heat (Fahrenheit). The fluid, by its static pressure against the piston, moves it with sufficient force to raise à weight upon an inclined plane, during the whole range of the impulse, and thus generating a power which at the termination of the impulse is capable of moving the valves or cock, and reversing the static pressure on the piston, which causes a new impulse in the opposite direction, during which the weight is again raised: thus each impulse generates a power capable of changing the position of the cock or valve, and produces a continuity of motion, expressive of the quantity of fluid discharged.

a b, fig. 1, (see Plate XII.) represents the cylinder, which I prefer to be laid horizontally, with the nozzles upward, in order that air (if there should be any) may readily escape on the introduction of the fluid to be measured; c and d, (fig. 2) are the guides for the piston rod, the cross bar of which works in the slits, at the end of which are adjusting screws, which prevent the piston from moving beyond its proper limits. ee are two guards, which being placed immediately under the range of the pin of the roller f, prevent it from falling until it has attained the ends of the guards e e, which are adjusted to suit the same limits of stroke as the pins in the guides e and d; the roller f, and connecting rod g, are made sufficiently heavy, either in their own substance or by weights added thereto, to VOL. IV. NO. 78. 1st January, 1830.

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