The erg, q. v. It is the same as the unit of energy, of which work is the corelative, being equal and opposite to the energy expended in doing it. There are many other engineering units of work, as the foot-pound and foot-ton.

In multiplex telegraphy the transmission of three messages simultaneously over the same wire. (See Telegraphy, Multiplex.)

In multiplex telegraphy the transmission of four messages simultaneously over the same line. (See Telegraphy, Multiplex.)

A simpler form of telegraph signaling than double curb working. It consists in sending a reverse current through the line for each signal by reversing the battery connection.

A method of telegraphy, in which the currents are reversed or alternated in direction.

In multiplex telegraphy the transmission of five messages simultaneously over one wire. (See Telegraphy, Multiplex.)

In multiplex telegraphy the transmission of six messages simultaneously over one wire. (See Telegraphy, Multiplex.)

A method of working telegraph lines. When a signal is sent the line is charged. This has to be got rid of, and is an element of retardation. In double curb working it is disposed of by sending a momentary current first in the reverse, and then in the same, and finally in the reverse [...]

In duplex telegraphy the sending of two independent messages from the same end of the line in the same direction.

A variety of duplex telegraphy in which the messages are sent from opposite ends of the line, simultaneously, so as to be transmitted in opposite directions. (See Working, Diplex.)