3247. When we turn to radiation phenomena, then we obtain the highest proof, that though nothing ponderable passes, yet the lines of force have a physical existence independent, in a manner, of the body radiating, or of the body receiving the rays. They may be turned aside in their course ... [They may be] turned on their axis ... Their sum of power is limited ... The lines have no dependence upon a second or reacting body, as in gravitation; and they require time for their propagation.
Published before 1923