Describes a semi-automatic viscometer which incorporates a microprocessor system and uses optoelectronics to detect flow of liquid through the capillary, flow time being displayed on a timer with accuracy of 0.01 second. The system could be made fully automatic with an additional microprocessor circuit and inclusion of a pump. (Author/JN)

Describes use of a Fresnel biprism to demonstrate double-slit interference with polarized light. Discusses polarization and phase properties of a randomly polarized gas. (JM)