An analysis is given of the controlling action of a vacuum tube in circuits similar to those proposed by Neher and Harper and Neher and Pickering. A modification of the latter's circuit eliminating some of its disadvantages is described. This circuit has been incorporated into a four tube network which controls the counter, scales down the impulse rate by any desired factor, and records the scaled counts. A new circuit is also described for recording the impulses from a single counter or from counters connected in coincidence.