with no perceptible variation in intensity. The light is turned on or
off with a thumb screw. Wires have already been put into forty
buildings."

My father had anticipated the incandescent light in its fuller later
development and had used, before it was announced by Prof. Avenarius of
Austria, a method of dividing the electric current, by the insertion of
a polariser in a secondary circuit connected with each lamp, a method,
it need not be said to electricians, now utterly obsolete.

The rooms of our physical laboratory at Irvington were almost all lit by
electric lamps constructed somewhat on the principle of Edison's, but
using platinum wires, and the old residents of that village may recall
the singular, lonely house half hidden in broad sycamores, sending out
its electric radiance late at night while my father and frequently
myself, then a boy of thirteen years, worked at experimental problems in
physics.

My father gave my precocity for science a very successful impetus and
left me at his death fully in possession of the ideas and projects he
cherished. Amongst these projects, one partially realized, was the
acceleration of plant growth by means of electric light, and heating by
electricity.

Dr. Siemens of England, it may be recalled, had very ingeniously
experimented upon the influence of the electric light upon vegetation.
In a paper read by that distinguished man before the Society of
Telegraph Engineers in June, 1880, he referred to his conclusion that
"electric light produces the coloring matter, chlorophyll, in the leaves
of plants, that it aids their growth, counteracts the effects of night