The Sun.
London, England, 1851-07-17 00:00:00

E I:: N IN G 5

CLY

THE OFFICIAL DESCRIPTION AND
ILLUSTRATED CATALOGUE OF THE
GREAT EXHIBITION.
HENLEY'S MAGNETO-ELECTRIC TELEGRAPH.

TO THE EDITOR OF THE SUN.
Sini—lf ever there was a time when inventors were
fairly entitled to a just and unbiassed criticism of their
productions, it is now, at the Great Exhibition of all
Nations, when acme, and wealth, and high standing are
expected, for once at least, to give way to the more le-
gitimate claims of original genius and persevering in•
dustry. I am not in any way connected . with the
Magneto-Electric Telegraph, but I call attention to the
description of this instrument, in the published exponent
referred to, just as a sample of the amount of justice
which inventors are to expect from the compilers of
official catalogues, unless they are keenly alive to their
own interest, and assert their rights tbrcugh other and
independent channels. The stet:ailed explanation of this
invention is more like an extract from some work on
general science than the description of anything in par-
ticular, and as illustrative of the matter of which it as-
sumes to treat, it is erroneous from beginning to end.
After a brief statement of the received theory of mag-
netism, the author (who signs hims.elt R. 11.) proceeds to
inform his readers, by what means a magneto-electric
disturbance is effected, so as to produce a continuous and
uninterrupted stream of electricity. Whereas in Mr.
Henley's telegraph continuous streams of electricity are
entirely dispensed with, and the necessary communica-
tions are effected by a succession of momentary waves or
impulses, each of which is made to produce upon the in-
strument a totally distinct and independent action. The
writer then goes on to inform us that " the magneto-
electric machine was first employed for telegraphic pur-
poses by Professor Wheatstone." This statement would
lead any one to suppose that the present invention was
wanting in novelty, and was borrowed from the original
ideas of Wheatstone. The real facts of the case, how-
ever, are in direct opposition to any such conclusion.
The first person who ever applied Faraday's discovery
to the working of a telegraph was Dr. Stenheil, of Bava-
ria, Afterwards, it is true, Professor Wheatstone con-
structed an instrument upon this principle, and tried it
upon two different sections of the Great Western Rail-
way. The telegraph which he employed indicated by
means of an escapement, or what is commonly known
among electricians as the step by-step motion. It
was found inoperative, and after a brief trial was
hid aside, and has never been used since.
To Mr. Henley the merit is due of having first practi-
cally applied the ma..lneto-electric power to the move-
ment of the needle telegraph, and of obtaining a result
which, for simplicity, power, and economy, has received
the unqualified approbation of many of the leading
scientific men of Europe, and some of the first engineers
of the age. The author cannot surely be acquainted
with the numerous and trying experiments to which
this instrument was successfully subjected on the South
Devon Railway, or with the still more decisive demon-
strations which were recently given in Hyde Park and
'across the Serpentine, and which one would have
thought were by this time patent to the whole scientific
world. If, however, he is really desirous to examine

into the justice and validity of his extraordinary conclu-
sions, and to ascertain the correctness of his terminat-
ing assertion, that the ordiAry voltaic battery is usually
preferred in this country to any application of magneto-
electric agency, I will not refer him to any printed re-
cords of past experiments, abundant and decisive though
these are, but I will ask him to see and judge for him-
self, and to institute the most trying experiment he is
able to devise upon any line in the kingdom, in order to
ascertain the comparative excellences of the two ar-
rangements, and I have no doubt he will find the inven-
tor most ready to assist him in the trial.
I am, Sir, your obedient servant,
J. B.

I-Anxious. as we have repeatedly shown ourselves to
be, in maintaining the rights of inventors, and in for-
warding the cause of philosophical inquiry, we have with
pleasure inserted the above communication of our cor-
respondent.—En.