Optically Worked Double Convex Glass Lens, 75mm Diameter, 100mm Focal Length Entomology & Zoology_Zoology Charts & Models sliding freely through the ring

sliding freely through the ring when cool but arrested once flame heating expands the ball beyond fit

Drives gel electrophoresis and other elevated-voltage experiments at 70V DC up to 300mA through a pair of safety sockets

Larger right-angle glass prism at 2 by 2 by 2

this polypropylene graduated cylinder set is Class B-tolerant

5-inch stainless steel connecting rod

Optically Worked Double Convex Glass Lens, 75mm Diameter, 100mm Focal Length Entomology & Zoology_Zoology Charts & Models sliding freely through the ringOptically worked double convex glass lens at 75mm diameter and 100mm focal length, the f 1. 3 geometry favoring strong convergence and bright real image formation across a wide aperture.