Jenkins Duplex Machine
The Jenkins duplex cylinder type of machine was designed for simultaneously sending and receiving photograms, letters, maps, drawings, etc. The motor runs all day long, like an electric fan, in control of the vibrating fork. The right hand (glass) cylinder sends; and the left hand cylinder receives. The messages are put on and taken off without stopping the machine, and without one function interfering with the other.
The machine may be used on radio or on wire, and is an easily operated machine, the perfect functioning of which can be determined by a glance at the perforated rotating disc illuminated by the synchronizing signal lamp.
It is believed to be the first duplex two-way service machine ever built, and is complete as shown, except for the batteries and the radio receiving set, which latter may be any standard set which will operate a loudspeaker.
The illustration shows a machine in which a picture transparency and a sensitive cell is used at the sending cylinder; and a high speed lamp and photographic paper at the receiving cylinder.