Antique Typewriters

The Martin Howard Collection




The Omnigraph with box relay

The Omnigraph with box relay


The Omnigraph Mfg. Co.
13-19 Hudson Street, New York, NY

The Omnigraph was patented in 1904 and was designed as a teaching tool to help beginners learn Morse code and how to operate a telegraph station.

It was described as "A new and useful improvement in instruments for the teaching and practice of morse code telegraphy". This model is the top of the range Deluxe model with an original price of $14.00.

The stack of 15 aluminum discs have 'saw tooth' projections cut into their edges. The windup movement rotates the discs while a stylus rides the bumpy edge of the discs, making and breaking the electric circuit. This electric signal is sent by wire to the sounder box, which houses an electro-magnet and a sounder that produces the familiar Morse code sound.

The possible variations of signal are almost infinite. Five arms projecting from underneath the discs move the tracking lever to the next disc. By retracting all five arms no move takes place and a single disc signals continuously over and over again. Leaving one arm projecting, the tracking lever follows a complete disc before moving to the next disc. Bringing more arms into use results in a track change every time an arm passes the track-changing mechanism. To obtain even greater variations in the code sequences, the discs can be taken off the machine, twisted round in relation to each other, or shuffled, before being put back to obtain a completely different series of signals as the machine again goes through the various track changes described above.

For learners there was a wide range of discs available, providing practice in American Morse or Continental code, including the alphabet in rotation / single letter discs / numeral / punctuation / railroad / commercial / and press systems / plus interchangeable practice messages.