“For these reasons, Dr. Brewster’s invention seems to me quite unlike the other two. Indeed, as far as I know, it is quite singular among optical instruments; and it will be matter of sincere regret, if any imaginary or vague analogy, between it and other optical instruments, should be the means of depriving the Doctor of any part of the reward to which his skill, ingenuity, and perseverance, entitle him so well.
“John Playfair,
Professor of Natural Philosophy in
the University of Edinburgh.”
“P.S.—Granting that there were a resemblance between the Kaleidoscope and Bradley’s instrument, in any of the particulars mentioned above, the introduction of coloured and movable objects, at the end of the reflectors, is quite peculiar to Dr. Brewster’s instrument. Besides this, a circumstance highly deserving of attention, is the use of two lenses and a draw-tube; so that the action of the Kaleidoscope is extended to objects of all sizes, and at all distances from the observer, and united, by that means, to the advantages of the telescope.
“J. P.”
Professor Pictet’s opinion is stated in the following letter:—
“Sir,—Among your friends, I have not been one of the least painfully affected by the shameful invasion of your rights as an inventor, which I have been a witness of lately in London. Not only none of the allegations of the invaders of your patent, grounded on a pretended similarity between your Kaleidoscope and Bradley’s instrument, or such as Wood’s or Harris’s theories might have suggested, appear to me to have any real foundation; but I can affirm, that, neither in any of the French, German, or Italian authors, who, to my knowledge, have treated of optics, nor in Professor Charles’s justly-celebrated and most complete collection of optical instruments at Paris, have I read or seen anything resembling your ingenious apparatus, which, from its numberless applications, and the pleasure it affords, and will continue to afford to millions of beholders of its matchless effects, may be ranked among the most happy inventions that science ever presented to the lovers of rational enjoyment.
“M. A. Pictet,
Professor of Natural Philosophy in
the Academy of Geneva.”
Those who wish to examine farther the ancient combinations of plane mirrors, and other subjects connected with the Kaleidoscope, are referred to the following works:—
Baptista Porta’s Magia Naturalis. Kircher’s Ars Magna Lucis et Umbræ. Schottus’s Magia Universalis Naturæ et Artis. Bradley’s Treatise on Planting and Gardening. Harris’s Treatise on Optics. Wood’s Optics. Dr. Roget on the Kaleidoscope, in the Annals of Philosophy, vol. xi. p. 375. Encyclopædia Britannica, Art. Kaleidoscope, by Dr. Roget; and the Compte Rendu des Travaux de L’Académie de Dijon, pour 1818, pp. 108-117.
Works by SIR DAVID BREWSTER.