Optically Worked Double Convex Glass Lens, 75mm Diameter, 300mm Focal Length Glassware_Glass Flasks Double-concave glass lens at 50mm

Double-concave glass lens at 50mm diameter and 250mm focal length on a 4mm-thick blank

designed so seated students read the needle without parallax error from a steep viewing angle

Nylon ball-bearing pulley with a bench-clamp fitting for edge-mounting on a worktable

Hand-painted female pelvis model exposes ilium

including the hydroxyl group central to alcohol chemistry

Optically Worked Double Convex Glass Lens, 75mm Diameter, 300mm Focal Length Glassware_Glass Flasks Double-concave glass lens at 50mmLong focal double convex glass lens at 75mm diameter and 300mm focal length, the f 4 geometry pushing focal point well downrange for projection style image formation demos.