Nikola Tesla U.S. Patent 725,605 - System of Signaling Patent Wrapper Page 74

688 6 since a succession of waves or impulses of different characteristics may be produced by an instrument having but one such circuit. A few of the many ways which will readily suggest themselves to the expert who applies my invention, are illustrated in Figs. 3, 4, and 5. In Fig. 3 a transmitting system e s3 is partly shunted by a rotating wheel or disk D3, which may be similar to that illustrated in Fig. 1, and which cuts out periodically a portion of the coil or conductor, or, if desired, bridges it by an adjustable condenser C3, thus altering the vibration of the system e $3at suitable intervals and causing two distinct kinds or classes of impulses to be emitted in rapid succession. by the sender. In Fig. 4 a similar result is produced in the system by periodically short circuiting, through an induction coil L3 and a rotating disk D4, with insulating and conducting segments, a circuit p in inductive relation to said system. Again, in Fig. 5 three distinct vibrations are caused to be emitted by a system es, this result being produced by inserting periodically a suitable number of turns of an induction coil L4 in series with the oscillating system by means of a rotating disk B5 with two projections 5 5, and three rods or brushes n5, placed at an angle of 120 degrees relatively to each other. The three transmitting systems or circuits thus produced may be energized in the same manner as those of Fig. 1, or in any other convenient way. Corresponding to each of these cases, the receiving station may be provided with two or three circuits, in an analogous manner to that illustrated in Fig. 2, it being understoca, of course, that the different vibrations or disturbances emitted by the sender follow in such rapid succession upon. -9