XXVII. On the nature of the force producing the motion of a body exposed to rays of heat and light

Abstract

Mr . Crookes has lately drawn attention to the mechanical action of a source of light on delicately suspended bodies in vacuo . I have made a few experiments which will, I think, throw some light on the cause of these phenomena, and assist us in the explanation of the manifold and striking experiments made by Mr. Crookes. Whenever we observe a force tending to drive a body in a certain direction we are sure to find a force equal in amount acting in the opposite direction on the body or on the bodies from which the force emanates. It was with the view of finding the seat of this reaction that I have made the experiments described in these pages.