One of the tunnels through the Alleghanies, now constructing on the line of the Pennsylvania Railroad, is to be 3,570 feet in length. Its area, at the widest space within the lines of the masonry, will be about 24 feet, and the spring of the arch wil begin 16 feet from the crown of the arch. About 400 men are employed upon it. Improvements in Upright Pianofortes The annexed engravings are views of improvements in Upright Pianofortes, invented by R. E. Letton,of Quincy, III., and for which a patent was granted the 5th of last October, (1852). The invention consists in a certain arrangement of the sounding-board, metallic plate, and bridges; also in the action “ or striking part. Figure 1 is an elevated view of the metallic plate, sounding-board, &c., and fig. 2 is a side elevation of the striking part. The Ji'indiid il!t- fast tw\> iIlJlpro;erne»ts lay in the fact that, in almost all pianofortes, the upper notes are weak and greatly deficient in fullness of tone. This is owing to the ne. cessary shortness of strings, and the extreme nearness of the bridge to the edge of the sounding-board, by which each string becomes shorter and shorter, consequently has less and less vibration, and of course a diminution of tone as the bridge, which the short strings cross, approaches the edge of the sounding-board. This difficulty is greatly obviated by the metallic plate, I, fig. 1, which is secured to the frame a short distance in front of the sounding-board. The upper part of this plate, which carries the rest, b b, for the upright or shorter strings, J J, extends some distance over the sounding-board, and is supported firmly by blocks, C C, which pass through the sounding-board, and rest (fglrn t til.. standards in thehark of the frame The reason for extending the plate, I, over the sounding-board, is to bring the upper part of the bridge, K, over which the shorter strings pass, nearer to the' centre, and thus to give the upper notes the full benefit of the vibration ofthe sounding-board, and render them full and firm, that is, more flute-like, and not Fi re 2. wiry and thin. The fact that the sounding- board can be more easily set in motion near its centre, than at the edge, can be proved by a common illustration: thus, place the two ends of a board on blocks, the nearer to the centre a person stands on the board, the more easily is it sprung. The same difficulty takes place in the bass strings, but the great length of these strings,and the consequent strong vibration, overcomes the lack in the sounding-board. All persons acquainted with upright pianofortes, know their want ot freedom to the touch; a performer is not able to play with the same expression as on the square or grand piano-it is not so sensitive to the light touch owing to the complicated combinations in the actions in order to reach the upper end of the strings. This improvement consistsin con- strueting a simple and free action, and placing the strings within its reach, instead of additional machinery to reach the strings. This i accomplished by the bass or long oblique strings, F F, which are attached to or pass round pins in the metal plate or bracket, L which is secured in nearly a vertical position in front of the metallic plate at the lower right hand corner, fig. 1; from thence they pass over the bridge, M, which rests on the sounding- board (an opening being made in the metallic plate to admit the bridge) , from thence, crossing in front of the strings, J J, they pass over a curved bridge, N, which is firmly secured in a nearly horizontal position to the top timber or tuning block, C, terminating in the upper left-hand corner of the case. By this arrangement the greatest possible length of string is obtained. The bridge, N, is brought a little lower than the end of the metallic plate, in order to bring the long strings within reach of the action, it being necessary to strike the string within a certain distance of the end, to produce the greatest tone. In figure 2, the action is all attached to the key-board, 0, where the end of the key-board and one of the strings is shown, and that will be sufficiant to explain the operation of the hammers on all the strings. P is the key; Q R is a bent lever, termed the jack, which hangs on a pivot, g; in a small block upon the back of the key, an upright wire, A, is secured in the top of the key, and passes freely through the arm, Q, of the bent lever. This wire is screwed and furnished above the arm, Q, with a button or nut of leather or other material, i, which is adjustable at various heights to regulate the height of the end of the said ami, which is thrown up against it by a spring, J, placed between it and the key. By thus adjusting the arm Q, the arm R is adjusted to bring its point or upper end to any required position. Attached to the back edge of the key-board, 0, there is a perpendicular board, S, running the entire length ofthe key-board ; to this board all the blocks, K, which carry the hammer butts, T, are attached. The hammer hutt hangs on a pivot, d, and carries the hammer, », in the usual way. When the key has been depressed, the hammer is then thrown back immediately after striking, by the weight of the butt, which is extended in the form of a low aq:n. This part of the butt, T, rests, when the key is left free, upon a button, e, at the upper end of the wire, h, and in that position it is repTP itfsfin tile figure. This button, t, is adjustable on a screw on the wire, to regulate the fall of the hammer. On the under-siSe ©f the arm, T, there' is a small cushioned block or projection, p, the office of which is to fall on the button, e, immediately alter the hammer has struck and while the key is retained; the button, e, thus acts as a stop, and prevents the entire descent of the hammer, by only allowing it to fall back a short distance, enabling the operator to repeat a note a number of times in rapid succession. The button, e, by being adjusted at a proper height on the wire, h, is also intended to leave the point of the arm, R, of the jack free of the butt when the key is free. The by is shown in shaded lines as depressed, the hammer being in the act of striking, and just about to iali back. It will be understood, by referring to the shaded lines, that the point of the key lever, in throwing up the hammer, arrives at the vertex of the shoulder, m, and then passes it, leaving the haJ.Ilmer free to fall back and bring its cushioned block, p, to the button, 0, which it does instantaneously, without perceptibly displacing the key lever, thereby rendering the notes sure and quick. ' The frame is made in a substantial manner, with oblique braces and oblique iron bars, to resist the opposite strain of the lone; or bass strings. About the upright position of the pianoforte it is useless tosay anything, for in this compact form it occupies much less space than in any other position, and therefore is a more convenient, and more graccful article of lumi* ture. More information may be obtained by letter addressed to the patentee.