Experiment in optic rays. 

 - Videocassette (VHS)(ca. 30 min.) :sd., B&W. 1/2 in. 
<br/><br/> The film is intended not for pupils, but for teachers to encourage a new approach to their subject. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Optic rays.