to the second digital indicator 90 via a storage register 92 in order that the second indicator be made random with respect to the first indicator the gate 86 is energized with a 60 cycle dither so that the wave form input to the counter 88 is as illustrated due to the low tolerances of the circuit apparatus there is thus no consistent correlation between the outputs indicated on the displays 76 and 90 and they may be said to have no interrelationship as the flip flop 78 is reset the output is fed through line 94 to a 10 pulse generator 96 which generates 10 pulses that are fed into the accumulating counter 74 these 10 pulses cause the counter to count through one complete cycle back around to where it was before the 10 pulses because of the speed at which this occurs there is no noticeable occurrence of this additional count on the indicator 76 as the counter 74 counts past zero a carry signal is generated and introduced into the set input of a flip flop 98 the output of the 10 pulse generator 96 is also fed into the accumulating counter 88 through a gate 100 which is driven by the flip flop 98 since the flip flop 98 is set by the carry from counter 74 and this carry will be generated when a number of pulses equalling the 10.