a furnace was erected in the yard of the Royal Institution; and it
was at this time, and with a view of assisting him at the furnace,
that Faraday engaged Sergeant Anderson, of the Royal Artillery,
the respectable, truthful, and altogether trustworthy man whose
appearance here is so fresh in our memories. Anderson continued to
be the reverential helper of Faraday and the faithful servant of
this Institution for nearly forty years.[5]

In 1831 Faraday published a paper, 'On a peculiar class of Optical
Deceptions,' to which I believe the beautiful optical toy called the
Chromatrope owes its origin. In the same year he published a paper
on Vibrating Surfaces, in which he solved an acoustical problem
which, though of extreme simplicity when solved, appears to have
baffled many eminent men. The problem was to account for the fact
that light bodies, such as the seed of lycopodium, collected at the
vibrating parts of sounding plates, while sand ran to the nodal
lines. Faraday showed that the light bodies were entangled in the
little whirlwinds formed in the air over the places of vibration,
and through which the heavier sand was readily projected. Faraday's
resources as an experimentalist were so wonderful, and his delight
in experiment was so great, that he sometimes almost ran into excess
in this direction. I have heard him say that this paper on
vibrating surfaces was too heavily laden with experiments.


Footnotes to Chapter 2

[1] The reader's attention is directed to the concluding paragraph
of the 'Preface to the Second Edition written in December, 1869.
Also to the Life of Faraday by Dr. Bence Jones, vol. i. p. 338 et seq.