Overhead projector has been a favorite presentation tool
The overhead projector has been a favorite presentation tool for educators and business people alike. Its origins in technology go back to the turn of the century, but in the late 1950s and early 1960s, the Minnesota Mining and Manufacturing Company 3M introduced the use of transparency film for educational purposes and became a major manufacturer of overhead projectors. With the projectors user manual and a little practice time, youll be ready to give your own presentation.
