The annexed engravings are views of an improvement in Pianofortes, invented by Alfred Speer, and Ernest Marx, of Aquackanonk, N. J., and for which a patent was granted on the 28th of last September (1852). Figure 1 is a perspective view of the instrument; fig. 2 is a front view, with the keys, sounding-board, and strings exposed. Fig. 3 is a perspective view, showing the sounding-board with all the parts to which the strings are connected. The same letters refer to like parts. The improvement relates to the sounding-board of these instruments, and consists in making the same in the form of a hollow cylinder, cone, or prism, or part of such figures, the said board having its ends secured between two discs or heads. The strings, cap, tuning-block, and all. parts of the instrument are suitably arranged around it to produce the sound. The principal object of making the board of this form, is to improve the sound,— afford facilities lor making double instruments with more than one set of strings in a single case, &c. The instrument is very ornamental indeed ; it can be made of a gothic, or any other pattern, and will form a more beautiful piece of parlor furniture than the common pianoforte. A isthe sounding-board, which is represented to be in the form of a hollow cylinder; it is secured between two strong wooden discs, B C (fig. 2), which are well braced together by braces or by tension rods. The top disc C, serves for a tuning-block, the tuning pins, I 6, being screwed into its periphery. E is the cap, made of cast-iron ; its form is part of a cylinder, so that all parts of its face may be at an equal distance from the sounding-board : it rests upon, and is firmly secured to the disc B, having a deep flange, which extends ove] the outside of the disc; it is recessed around ?itddjto fit over the periphery of the disc, sc as to make the combination secure and firm; e e are the strings, only a few ot which are shown ; they are secured in loops to the pins, I//, in the cap, and pass through holes, then over the bridge, g A, to the tuning pins, 6 6, in disc C. The sounding-board, as shown in the engraving, is a perfect unbroken cylinder, which the patentees believe to be the best, but any of the forms heretofore specified, as embracing the principle, may also be employed. This instrument has a sounding-board of two feet in diameter, and is six feet high, consequently it is six feet and four inches (nearly) in circumference, or a little over thirty-seven square feet. This great surface, together with the cylindrical form oi the sounding-board, the makers assure us, greatly improves the tone of the instrument, both as respects sweetness and strength. The strings being arranged around the sounding-board, are not so liable to get out of order as those arranged on one side. Two, three, or more sets oi strings may be arranged round one sounding-board ; and with keys for each set, a number of performers may be able to play at the same time, and yet no more room would be occupied than with a common flat piano. Its form allows of its being placed at the side, or the centre of a room, and yet have full length strings. More information may be obtained by letter addressed to the patentees.