. Appleton's dictionary of machines, mechanics, engine-work, and engineering. The signal-key, in its more perfect construction, is represented in Fig. 3392. It consists of a lever,mounted on a horizontal axis, with a knob of ivory for the hand at the extremity of the long arm, whichis at the right in the figure. This lever is thrown up by a spring, so as to avoid contact with the buttonon the frame below, except when the lever is depressed for the purpose of completing the circuit. Aregulating screw is seen at the extremity of the short arm of the lever, which graduates precisely theamount of
. Appleton's dictionary of machines, mechanics, engine-work, and engineering. The signal-key, in its more perfect construction, is represented in Fig. 3392. It consists of a lever,mounted on a horizontal axis, with a knob of ivory for the hand at the extremity of the long arm, whichis at the right in the figure. This lever is thrown up by a spring, so as to avoid contact with the buttonon the frame below, except when the lever is depressed for the purpose of completing the circuit. Aregulating screw is seen at the extremity of the short arm of the lever, which graduates precisely theamount of motion of which it is at any time capable. fc_J The registering part of Morses telegraph is shown in Fig. S393. Two screw-cups are seen on theboard, intended for the insertion of the wires from the distant battery. Next the screw-cups is soon aU-shaped electro-magnet, with coils of wire upon it, the ends of which, passing down through the board,are connected with the screw-cups. Over the poles of the magnet is a little armature, or bar of softiron, attached to the short arm of a lever, whose long arm carries a point or style, nearly in contactwith the grooved roller above. The action which takes place, on depressing the signal-key at the distaut station, is, in the simplest terms, as follows: A wave of electricity is transmitted over the wire ofthe telegraph, arrives at the electro-magnet, and circulates through the coil o( wire surrounding it. TheU-shaped soft iron becomes at once a magnet, (see Magnetism,) and attracts the little armature downto it. The long arm of (he lever is thrown up, and marks the strip of paper passing
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Keywords: ., bookcentury1800, booksubjectmechanicalengineering, bookyear1861
