Using organic crystals or liquids as scintillators and 1P21 photomultipliers as detectors, a delayed coincidence circuit has been designed for measuring nuclear lifetimes in the region 10−10−10−7sec. The pulses from the photomultipliers were amplified in distributed amplifiers and applied to a germanium diode bridge coincidence circuit.The apparatus has been used for measuring scintillation decay times, the lifetimes of nuclear transitions, and the time of flight of light over distances of the order of one meter.