Variable Angle Glass Prism, 15° x 15° x 150° Size_Medium sized for fine-print reading and

sized for fine-print reading and convex-lens image-formation work in introductory optics

sized to accept a bell jar for atmospheric-pressure and vacuum demonstrations

Single-pole double-throw switch on a demonstration base

Charged porous pot with a zinc rod inside a rectangular polythene jar

Pairs 100mm of length with 25mm faces on a polished acrylic equilateral prism

Variable Angle Glass Prism, 15° x 15° x 150° Size_Medium sized for fine-print reading andGlass prism with a 15 degree apex and 15 x 15 x 150 angles, the doubled apex prism producing about twice the deviation of the 5 unit while still in the small angle regime.