The use of audio-visual aids in teaching is accepted today by most educators. One of the most vivid aids is the 16mm motion picture projector. The use of audio-visual aids is rapidly assuming ever greater importance in all schools. As the operation of motion picture projectors is a part of audio-visual instruction, it is important that all teachers learn how to operate them while taking audio-visual courses. Techniques of instruction may vary from only a demonstration of one projector in some colleges to many hours of supervised practice on many projectors in others, but all colleges are striving to give the recipients a maximum of proficiency in a minimum of time.