Morkrum-Kleinschmidt printing telegraph systems

After comparisons between the more successful schemes adopted commercially for automatic telegraph working associated with the names of Hughes, Baudot, Wheatstone, Murray, Wright and Creed, the author gives a general account of the developments of the Morkrum Co. resulting in the "start-stop" five-unit system ("Teletype") adopted extensively in the U.S.A. and elsewhere. The modifications and difficulties encountered in the various modes of operation of telegraphic printing, e.g., whether multiplex or not, page or tape printing, perforated tape or direct keyboard, are enumerated. The use of multiplex necessitates accurate synchronism between the rotary switches, and the system adopted is of general interest. The driving motor is a small rotary converter. Sufficient power is supplied on the d.c. side for running at a speed near synchronism; the machine is then locked into step by supplying a.c. generated by make-and-break contacts on a self-maintained tuning fork.