. This is fairly complete history of electronic computings origins however there were several electric (relay logic) designs not mentioned here. While slow they capitialized on the then fairly mature telephone realys of varying design. They were generally of two types the contactor or n-pole double throw or the stepping(counting) with typically 11 positions. The later could be used to make counters or registers. In the early years (pre about '44) these were used to make calculator type machines of the programmed or fixed type. Allison