Science: Leonardo's Machines

That old master of all trades, Leonardo da Vinci, had so many ideas he could never get around to putting them all into practice. His notebooks are filled with detailed drawings of unfinished projects that have always fascinated his latter-day admirers. In its Manhattan headquarters last week, the International Business Machines Corp. put on display a traveling exhibit of 66 models of Leonardo's inventions, built to the master's own specifications by an Italian engineer named Roberto A. Guatelli, who helped build an earlier exhibit in 1939 (TIME, May 29, 1939).

Most of the models work, and all look much too modern to have been invented 450 years ago. One of Leonardo's water turbines is almost up to date. So is his odometer, a device to measure distances by counting the turns of a wheel. His mechanical jack looks as if it had been designed for changing tires on a modern automobile. If Leonardo had had a gasoline engine, his tank (with breech-loading cannon and independent spiked wheels) might have been effective during World War I.

Some of Leonardo's inventions were actually built and used. His canal locks are still in operation near Milan, and they work just like the locks of the Panama Canal. But Leonardo was often too far ahead of his contemporaries. His paddle-wheel boat, his cantilever swing bridge, his pumps and his air conditioner (both driven by water power) did not fit the crude technology of the 16th Century. Centuries had to pass before the slow-moving world caught up with Leonardo.