MIRROR USED TO SHOW SPOT PLATE TESTS G. P. PERCIVAL University of New Hampshire, Durham, N w Hampshire
An ordinary twenty-five cent mirror (glass size 9'/2 inches by 71/2inches) and a metal coat hanger from the dry cleaners are all the equipment needed to show spot-plate tests to an audience. Straighten out the
wire hanger, and then bend it to form a support, so that the mirror on its side will lean over the plates a t an angle. Thecolor developed in the spots is reflected and can easily be seen by an audience even in a large room.