A high-resolution, high-precision mechanical flying spot digitizer (FSD) operating on-line to an IBM 7094 computer makes available to the computer some 20,000-50,000 coordinate pairs describing a bubble chamber picture in a time of a few seconds. The computer is guided by humans in its selection of relevant data -- normally by a few rough coordinates recorded in punched cards during a pre-scan, but also by a manual over-ride at the 7094 console in the event of failure in recognition at the time of precision measurement. The system is capable of transition to purely machine recognition as computer programs acquire sufficient subtlety and reliability. The Mark II FSD at Brook-haven is capable of 10 micron resolution and 1-2 micron accuracy over a 2" x 6" area of the photographic negative. Completed systems at Brookhaven and at the University of California in Berkeley are each processing strange-particle events at about the rate of 10 conventional measuring machines, with a further expansion in rate by about an order of magnitude envisioned. Similar systems are under construction at eight other laboratories in the United States and Eurone.