The numbers 6, 1, 2, 3, 4 and 5, represent keys of thin brass, and elastic, and are each fastened to a wooden support, D, D, by means of two screws. These keys are continued under and project beyond, the brass bar, L and L, which is supported by two standards, R and R. Whenever these keys are not pressed upon, they are each in metallic contact with the bar, R and R. The numbers 7, 8, 9, 10, &c. represent ivory buttons with a metallic stem beneath them, passing through a hole in the spring, or key, and on the lower side of the spring the stem is enlarged, so as to form a kind of hammer, designed to make a metallic contact with the two brass bars, beneath the springs, and represented as supported by the standards, N and N and P and P. Each of the buttons have a small wire spiral spring, to which they are fastened, and the small spring is itself fastened to the larger spring. O represents the galvanic battery, with its poles in connection with the two metallic bars, N and P.
[Figure 59] represents a side view of the key arrangement. F is the platform. E the wooden support of the six keys. H is the larger spring, or key, secured to the support by screws, h. The spring is observed to project beyond the metallic cross bar, L, after passing beneath it. R is the support of the cross bar, L. N and O are two of the ivory buttons, upon their spiral springs, a and c. Below the button, O, is a shoulder, formed at i, upon the stem which passes through the spring, H, and another shoulder is formed by the hammer, u, below the spring. It will be observed, that two buttons of the same key are never used at the same time. If the button, O, is to be pressed down, the weaker spring, c, will permit it to descend until the upper shoulder comes in contact with the larger spring, H, when more pressure is applied, and that spring is brought down, breaking its contact with the metallic cross bar, L, until the hammer, u, comes in contact with the metallic plate, n, upon the support, K, and as the plate, n, is connected with N pole of the battery, the connection is formed with it. It will, however, be noticed, that the button, N, not being pressed upon, will not, (though it descends with the larger spring,) be brought in contact with the other plate upon the support, J, and connected with the positive pole of the battery. To the end of each spring, a wire, S, is soldered, the purpose of which will be shown hereafter.
Fig. 59.
Fig. 60.
[Figure 60] represents an end view of the key arrangement; a, b, c, d, e, f, are the buttons, M and M the metallic cross bar, beneath which are seen the ends of the six larger springs, 6, 1, 2, 3, 4 and 5. R and R are the supports of the bar, M and M. G is the platform. W is the support of the metallic plates, with which the hammers of the little keys, or buttons, come in contact. S the wire leading to the battery.