"John B. Bunch" <[log in to unmask]> writes:
 
>Robin,
>        The materials you are looking for are called
>"pola-tape."  A small motor with a rotating polarized filter
>was attached to the bottom of an overhead projector lens:  the
>parts of the overhead transparency where the tape had been
>applied gave the optical effect of liquid motion.  Las I know,
>there was a company in King of Prussia Pennsylvania marketing
>these things but I do not have a name or addr.
>        It used to be fairly common in the Audio-Visual field.
>If I can get more information, I will let you know.
 
     Contact Edmund Scientific, I'm sure they have this in their
     catalog.
 
     Glen Jensen