Crookes Radiometer, 2.75" (70mm) Diameter, on Plastic Base Lab Supplies_Thermometers paired with a compound microscope

paired with a compound microscope to watch smoke particles jostle under molecular impacts

sized so students don't switch between two hand tools while preparing leads for student-built bench circuits

and ray-tracing experiments in introductory optics

and a second copper) for side-by-side comparison of conductivity and resistance

the wider-range Wheatstone-bridge reference

Crookes Radiometer, 2.75" (70mm) Diameter, on Plastic Base Lab Supplies_Thermometers paired with a compound microscopeEvacuated 2. 75 inch glass bulb on a plastic base with black and white vanes that spin under light exposure, the classic demonstration of differential radiant heat absorption.