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.
“Talking Machine” Photograms
The spring driven machine illustrated is probably the simplest device possible for the experimental study of transmission of pictures and picture messages by radio or by wire. A conducting ink or pencil line on paper and put on one cylinder (or an insulating coating cut through with a stylus) over which the sending point rides for sending; and an electrolytic bromide (or photo) paper on the other cylinder under the receiving pen for receiving; the contact points being attached to the sending and the receiving sets respectively.
The upper illustration shows a machine electrically driven and equipped to transmit and receive handwritings, maps, sketches, pictures, etc., of an area of about 5 × 7 inches. The sending is from pencil lines on paper, the reception on electrolytic paper.
The machine is also made with a glass cylinder to send from a picture transparency, and to receive on photographic paper. It must, therefore, be used in a dark or subdued lighted room to receive.
Each machine is capable of the very highest quality of work of its particular kind, and is simple and easy to operate.