L52 fi. CALCULATIONThe future of calculation, as depicted in the April 17, 1944 issue
of Newsweek. The potential of mechanical computing devices is
limited by wear and tear on its moving parts. A slide rule suffers
very little from such wear, but the more sophisticated adding ma-
chines of Pascal had to be designed with counterweights to delay
the inevitable lopsidedness that results from wear. Courtesy of
the Bodine Electric Company. Chicago.now known as a Turing machine. The crucial clement was programmability: Turing
envisioned a tape filled with information that could be fed into the machine. As
the machine read the information, it would modify its own internal state and then
move ahead or back to an adjacent instruction. In this way, Turing went a step