Hartley's Rotatable Optical Disc Material_Muslin with a (Br) marking visible

with a (Br) marking visible on one face for easy identification

brain anatomy

this analog DC microammeter measures 0-100uA at 2uA resolution on a tabletop housing

this Brownlee-pattern apparatus gives a clean visual proof of the 2:1 stoichiometry of water decomposition

a 125 by 65 by 18mm acrylic rectangular block with beveled edges widens the visible refraction shift in Snell's law setups

Hartley's Rotatable Optical Disc Material_Muslin with a (Br) marking visible230mm disc graduated 0 360 degrees in 1 degree steps locks in any position alongside a rotatable lamp house and six magnetic acrylic elements for full ray tracing studies of reflection and refraction.