Advanced Spectrometer with Turntable and Wooden Storage Case Glass Bottles_BOD Bottles producing audible beats when sounded

producing audible beats when sounded against its fixed-frequency partner on the matching wooden resonance base

Aluminum-cased 4-inch plotting compass with a glass face

introducing combinational-logic behavior by using physical relays so students can hear and see the gate state in real time

Louis open frame

and lever-principle demonstrations

Advanced Spectrometer with Turntable and Wooden Storage Case Glass Bottles_BOD Bottles producing audible beats when soundedAstronomical telescope with Ramsden eyepiece and cross hairs, three screw prism table, and a 0. 5 degree resolution turntable ship in a polished wooden case for advanced spectrometric work.