The telegraph manual: a complete history and description of the semaphoric, electric and magnetic telegraphs of Europe, Asia, Africa, and America, ancient and modern.

MODERN LEVER KEY. 435
current will pass through the brass frame A c G, the screw H II,
the axle of the lever at F, with the lever to the hammer and
anvil at E, and then with the wire attached beneath. When
the operator presses upon B, the lever descends and closes the
circuit at E, the weight of the back part of the key elevates
the front. This key requires an apparatus known as a " circuit
closer," which will shortly be described.
Fig. 12 represents a key with the "circuit closer" attached.
Fig. 12.
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A is a small lever, with an ivory knob on its end. In the
present position of the lever A the circuit is closed, but to move
it to the left at right angles with the key lever the circuit will
Fig. 13.