Text: "Light incident to any body that absorbs or reflects it does not press upon it. The radiometer of Professor Crooke's invention is not operated by the pressure of light, but by corpuscular bombardment on the reflecting side of its vanes. You have called my attention to the receding movement in the metal silver, which it assumes when the flow of an alternating current from an electromagnet, in front, is thrown upon it. This does not prove that light presses upon it to induce that movement. It moves by interatomic bombardment of some 800,000 corpuscular percussions a second, or more truly by intersympathetic vibrations. If a homogeneous disk of gold, silver and platina, in proper proportions, were made the medium of interference, the resultant action would be startling in showing up the movement of molecular antagonistic thirds. The movement would be very erratic and gyroscopic. If the same disk were used on an intermediate transmitter to a negative focalizer, or in other words, a polar radiator only one of which is in existence, by a nodal wire of gold, silver and platina, the effect on the disk at the negative terminus would to set into action the latent force held in its molecular embrace, and would cause it to sympathetically adhere to the focalizer with a power that would make it practically inseparable."

See Also: LIGHT

Source: 1