Brass spring fastened on edge to board, two binding posts and plug cut- out. This piece of equipment is called a plug or wedge cut-out. It was used to remove equipment from the line without opening the line more than an instant. It consists of a brass spring resting firmly against another pin or post. A plug or wedge is inserted between the spring and the pin. The plug is made of two pieces of metal separated by some insulating material. The instrument is fastened to the plug by set screw or binding posts attached to the two metal pieces of the plug. The spring of brass and post are referred to as a spring jack. The spring and the pin or post are attached by wires under the base to the two binding posts. The telegraph line or wire is connected to these binding posts. Some Spring Jacks and Plug Cut-Outs were also provided with lightning arresters and ground wire connections. This equipment was used in preference to a simple cut-out switch where it was desirable to remove telegraph apparatus completely from the circuit. This form was used also to remove batteries from the line and several might be used together, mounted on a board. In way-stations this form of cut- out was recommended for use in cutting out instruments when the operator left the office either temporarily or for the night and also during a thunder-storm. By pulling the plug from between the two pins the instrument was entirely disconnected from the telegraph line circuit, but the circuit was still closed or intact and the instrument magnet windings were protected from burning-out or shorting unexpectedly. The style of binding posts on this piece of equipment place it in the 1860s or 1870s. It is certain that this specimen is not later than 1895-6. The use of two posts to fasten the spring to the board would also seem to indicate the 1860s or early 1870s. Sources: Franklin L . Pope, Modern Practice of the Electric Telegraph, New York, 1891 (14th Edition) page 155-156; also the New York, 1871 (4th Edition) page 39. J. E. Smith, Manual of Telegraphy, 14th Edition 1878?, page 40. [GCM 1897]
