Note 29 — Chapter IV · SCIENTIFIC RESEARCHES: SECOND PERIOD.

“Experimental Researches,” i. 25, art. 85. This copper disc is still preserved at the Royal Institution. It was shown in action by the author of this work, at a lecture at the Royal Institution delivered April 11th, 1891. Fig. 6 is reproduced in facsimile from Faraday’s laboratory note-book.