Vacuum Pump Plate on Aluminum Base with Rubber Seal, 10" Diameter Entomology & Zoology_Zoology Models illustrating that sound cannot travel

illustrating that sound cannot travel without air

Reproduces Oersted's 1820 experiment

Highest-decade single-dial resistance box stepping from 100k to 1M ohms in 100k-ohm increments

suited to fieldwork in geography units and orientation activities outside the classroom

this microphone amplifier connects a microphone input to both an integrated speaker and an oscilloscope-driving amplified signal for waveform study

Vacuum Pump Plate on Aluminum Base with Rubber Seal, 10" Diameter Entomology & Zoology_Zoology Models illustrating that sound cannot travel10 inch vacuum pump plate on an aluminum base with a stopcock and rubber seal, sized to accept a bell jar for atmospheric pressure and vacuum demonstrations.