Radiometer Crook'S, Plastic Base, Evacuated Glass Bulb Have Black And White Vanes In Color. Mounted On Round Plastic Moulded Base, Comprising Partly Evacuated Glass Bulb Approx. 70 mm Diameter, Containing At Its Centre A Fine Pivot Which Supports Four Light Weight Metal Arms.
Ring And Ball, Mounted On Separate Handle Ball, Dia. 22mm, Consists Of A Brass Ball And A Brass Ring, Each Individually Mounted On Brass Rods With Wooden Handles.