CROOKES RADIOMETER DOUBLE Construction is same as above but having two bulbs with 2 sets of vane, when exposed to sunlight the vanes rotate in opposite directions. more...
Evacuated glass bulb of approx. 70mm dia having fine pivot at its centre which supports four light weight vane of mica 10 mm square approximately and blackened on one surface. Mounted on a bakelite stand. When exposed to sunlight or bright lamp the rotor rotates rapidly. more...