Optically Worked Double Convex Glass Lens, 75mm Diameter, 100mm Focal Length Entomology & Zoology_Zoology Charts & Models plus a removal tool in

plus a removal tool in a 4-compartment storage box

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

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

25mm enameled copper wire on a 355 x 50mm air-cored former with 4mm safety sockets and a 6A maximum

and acrylic in a foam-lined wooden case for density-versus-material investigations

Optically Worked Double Convex Glass Lens, 75mm Diameter, 100mm Focal Length Entomology & Zoology_Zoology Charts & Models plus a removal tool inOptically 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.