Note 17 — Front matter (continued 2)
Reading edition
It has sometimes been stated that the spark balls must be solid metal and no hollow, but this is a fallacy, and has been disproved by Mr. C. A. Chant. See "An Experimental Investigation into the Skin Effect in Electrical Oscillators," Phil. Mag., Vol. III., Sec. 6, p. 425, 1902.