Theater of Machines, Volume 4

screw, and in the same, the sleeves or screw-nuts original: "Schrauben-Mutterlein" which rotate with the screw and are driven by a rod or drawing-lever original: "Zieh-Bengel" and a hempen rope. For one first pulls these around with the hands; and to this end, the little wheels are marked with A, and the upper board B is placed, so that it might be somewhat separated and distinguished from the sleeves marked with C. In the two large boards E, which press and push downwards, thick walnut-wood original: "Nußbäumin" planks or boards are nailed; these should be very smooth, well polished, leveled, and firmly attached, indeed not with iron, but with wooden nails. The screws, however, have only a head or a ridge original: "Schranck", and are embedded in the large lower board with an internal notch original: "Einschnitt" marked with D, as is to be seen in the accompanying figure. On the other side, however, where there is no notch, wedges, basins, and onion-shaped supports original: "Zwibel" marked with F are driven in, so that everything holds together quite well, and nothing may shift to one side or the other.