The Sun.
London, England, 1856-10-25 00:00:00

THE STEREOSCOPE.

Sir D. Brewster ha addressed the following letter to
the Editor of the Tintes :
" Sir—ln the notice of Mr. Faye's stereoscope
which I soot you under the signature "A," not
thinking it of sufficient importance to add my name,
I claimed the invention of it for Mr. Wheatstone as

well as for Mr. Rhott, referring distinctly to Mr.
Wheatstone's paper. as published in 1838, and
to the later date of 1839, when Mr. Elliot executed his
instrument. I theref.re gave to Mr. Wheatstone all
the originality which he claims from prior publication.
But, as I had undoubted evidence that Mr. Elliot in-

vented the stereose3re in 1834, and as his form of the

instrument was exactly the same as Mr. Faye'F, while
Mr. Wheatstone'F, though equally ingenious, was diffe-
rent, I place Mr. Elliot's claim before Mr. Wheatstone's,.
I believe, therefore, that Mr. Elliot and Mr. Wheat-

stone are independent inventors of an instrument or me-
thod fnr uniting two dissimilar pictures, and thus pro-
ducing relief, but that neither of them discovered the
principle of the stereoscope. Mr. Elliot lays no claim to
such a discovery. Mr. Wheatstone does on the follow-
ing grounds. After quoting a curious experiment on
binocular vision, in which Leonardo da Vinci was on the
eve of inventing the stereoscope, he makes the following

observations :
" Had Leonardo da Vinci taken, instead of a sphere, a
less simple figure for the purpose of his illustration, he
would not only have observed that the object obscured from
each eye a different part of the more distant field of view,
brit the fact would also, perhaps, have forced itself upon
his attention that the object itself presented a different,
appearance to each eye. He failed to do this, and no sub-
sequent writer within my knowledge has supplied the
omission ; the projection of two obviously dissimilar pic-
tures on the two retince when a single object is viewed,
while the optic axes converge, must therefore be regarded
as a new fact in the theory of vision."—Philosophical
Transactions, 1838, pp. 372-3.
Now, this claim to the fundamental principle of the
stereoscope is groundless. Euclid knew it. Galen
knew it, and explained it. Baptista Porta quotes Galen's
explanation, and illustrates it with a figure. Aguilonius
in various parts of his Optics does the same, and in his
chapter on the vision of solids (ra ijrepea, to sterea)
he is puzzled in explaining how the two clis,itnilar pic-
tures give a distinct image in relief. Early in 1852, and
more recently, in my Treatise ode the Stere• scope, I have
quoted the passage from these authors to prove their
knowledge of the principle in question, and Mr. Wheat-
stone has made no reply to the statement. It is doubt-
less strange that he was not acquainted with the re-
searches of Galen, Porta, and Aguilonitie, for he tells us
(Phil. Trans., 1838, page 372) that, "after looking over
the wcrks of many authors who might be expected to
have made some remarks relating to this subject, he was
able to find but one which is in the Trate= della Pit
tura of Leonardo da Vinci." Among these works were
those of Pota and Aguilonius, and he has more than
once quoted both of them (pages 388, 390, 391, 393),
but, though I make this remark, I do not mean to in-
sinuate, nor do I believe, that Mr. Wheatstone saw the
passages to which I have referred.
In the extract from Mayo's Outlines, &c., from which
it is evident that Mr. Wheatstone was acquainted with
the principle of the stereoscope in 1833, and therefore
earlier than Mr. Elliot, there is no mention wtatever of
any instrument or method of combining the pictures. It
affords no proof that the reflecting stereoscope was then
in existence ; that he did combine them is obvious, and
if he had assured us that he did it by means of the re-
flecting instrument I should have implicit confidence in
the statement.
In concluding his letter, Mr. Wheatstone 'remarks
that I was the last person to have disputed the origi-
nality of his invention, as he can show from his corres-
pondence with me in 1832 " that I was aware that at
that time he was preparing for publication his memoir
on the subject." I therefoi e call upon Mr. Wheatstone
to publish this letter, or any part of it that has the
least reference to the stereoscope. If it has, I pledge
myself in future to 'place his claims above those of Mr.
Elliot, whenever I have occasion to write or speak on
the subject. Mr. Wheatstone's memoir is entitled
" Contributions to the Physiology of Vision," and I
may well have known that he was preparing it for
publication without the slightest knowledge that the
stereoscope was to be one of the 'various subjects of
which it treats.
As priority of publication is held by Mr. Wheatstone
to establish the "originality of an invention," it may be
sufficient to state to English readers that if this doc-
trine be admitted Sir Isaac Newton has no claim to
be the inventor of Fluxions. Leibnitz published the
method before him, but there is ample evidence that
Newton, was the earliest Inventor.
In the preceding observations I have avoided the
offensive personalities with which this subject has
been noticed in a silly article in the Westminster
Review. I have no personal feelings to gratify in giving
an opinion on this question. As the inventor of the
lenticular stereoscope now in universal use, and of
other forms of the instrument, I, of course, feel an
interest in the subject, and, involving as it does nice
questions in the theory of vision, that interest has been
greatly increased. In preparing lectures on the philo-
sophy of the senses I had occasion to study the depart-
ment of binocular vision ; and in the " Edinburgh
Transactions for 1843" I have given the true and de-
monstrable theory of t,qt stereoscope, after Mr. Wheat-
stone had wholly failed and acknowledged his failure
(Phil. Trans., 1838, p. 360). That theory has now been
before the scientific world for nearly 14 years, and has
never been controverted. When the paper which con-
tains it was written I believed that Mr. Wheatstone was
the sole inventor of the principle of the stereoscope, as
well as of the reflecting instrument, and I never failed to
give him the credit of both. He himself knows how I
was compelled to liivestigate the subject, and to estab-
lish the claims of others—of ancient authors to the prin-
ciple, and of Mr, Elliot to an instrument for exhibiting it.

THE ACCIDENT AT LLANSAMLET.—A Judge's order to
bail the Swansea station-master, against whom a verdict
cf manslaughter was returned by the coroner's jury.
having' been obtained, Mr. Hannon:le surrendered Lim-
self t. t Swansea on Wednesday afternoon, upon wLic'l to
was brought betel.° Mr. G. Grant Francis, and bound
over to appear at: the next. as.izes for the comity, under
hi-4 oivn recogmsauce for 510/., with Dr. Bird and Mr.
Glover in the like, for 2001. each. After the necessary
, forms had been gone thrcugh, and the documents signed,
Mr, liancorne was discharged.