New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1878-07-13
THE MICROPHONE.

SIR Inotice with regret that Mr.. Edison has
| been trying TO make the American public believe
that he also invented the mcrophone, and that sim
ply because in his carbon telephone he made use OF
button Of carbon, the varying pressure of a dia-
phraRm upon this producing varying current OF
electricity. In all his attempts as far as l can
learn he has never varied from this idea He has
made thin and thick diaphragms, tried many
kinds of carbon, ETC., but in all the
principle remains the same. The use of
carbon as a varying resistance, with varying
pressure, did not originate with Mr.. Edison. Mr.
Clerac electrician Of the French Government Tele-
graph Department. supplied me with resistance
tubes, founded upon this principle. in 1866; viz,
glass tube containing powdered carbon the resist
ance of which was regulated by the varying pres
Of a regulating screw pressing on the carbon.
Mr. Edison claims this resistance tube as an original
invention or discovery in 1873 seven years after
it was known in Europe. and he will fnd in
the Journal Telegraphiqae Berne, 1878, that
the invention was claimed by German
but on Mr.. Clerac proving his priority, 1856,
| it was freely accorded him. SO much for the
resistance carbon tubes of Mr. Edison and the prin-
| cipe of which he acknowledges he has adopted in
his carbon telephone AS a coincidence it is curl
GUS that the date-1873-Of Mr.. EdisOns claim to
these resistance tubes should be the same, when
the invention of 1866 again brought promi-
nently into notice by the remarks in the Journal
1eleTapkique. | am willing to believe Mr.. Edison
was ignorant of these facts until the present time
| but he ought now to investigate this and give
credit where credit is due.
| THE STRUCTURE OF THE MOROPHoNE.
| The micrOphone, the principle of which discOv-
ered and after many months incessant labor aud
study invented the numerous forms now in use Is
entirely different in principle, FORM uses and results
to the carbon trausmitter of Edison There is no
diaphragm thick or thin; there is mechanical APP
paratus by which the sounds directed or concen-
rated upon the electrical conducting material no
arrangement to obtain varying pressure, as we
need really constant one. There is not the slight
est necessity for the of carbon at the contact
points, as all metals which do not oxidize act
equally well The sOnOrOus vibrations are takenup
| by piece of pine board or any resonant material,
and if, on any part Of this board, no matter how
distant from the speaker OF source Of sound, two
electrical conductors are placed under very
slight but constant pressure these conductors
! vibrate exactly as the molecular agitation or
vibration of the board, and of themselves, without
any regulation, without any change of pressure
| transform a constant electric current into waves
| i'm exact form with the sonOrous vibrations. The
! effect is wonderful so much So that the highest
scientific ntellecs of Europe have been struck with
surprise and establishment. that such unheard-Of
effects could be produced from an apparatus and
| causes so apparently simple. In some of the forms
of rnicrophones use carbon at the contact points,
and, if believed for single instant that Mr. Ed
son was the first to carbon for electrical purposes
or for contact points, would use platinum or gold
points which equal to, if not superior to carbon
| though not 80 cheap but as carbon has long been
used in electrical batteries, electric light resistance
tubes and relay contacts by myself. see no neces-
sity to abandon its use simply because Mr.. Edison
happens to use it in his carbon telephone in totally
different way and for different reasons, from its use
! as contact points in the micrOphOne.
The London agent of Mr.. Edison, Mr.. Adams, pre-
sentod to the Post Office Telegraphs, about eight
weeks SINCE Edisons carbon telephone, and, as 1t
was publicly exhibited, l saw it III company with
many others. 1t consisted of an Edison transmtter,
and an exact copy ofProfessor Bells receiver, which
| he calls an Edison receiver
| The transmitter consisted of a diaphragm tsame
form and materials as Professor Bell's pressing
upon a button of carbon. the varying pressure Of
the diaphragm upon the carbon producing
varying current of electricity. 1t twas complicated,
required not only the use of batteries, but nduc-
| ton coils and the results not superior to
those of Professor Bells against which it was tried
| in my presence. The Edison receiver was lqenJl-
cally the same as Professor Bells, the only dlhSr
! ence being that the natural magnet was Drought
round so as to touch the dlaDhragm I'D laot u was
| so transparent a device TO infringe Bells patent
| that the Bell Company at once SAID they
| would not permit its use. MI. Edison
! thinks there are points OF resemblance De
! tween his carbon transmtter 10 PROFESSOR
! Bells telephone, and anything have dOne IL IS
quite proper subject for discussion IN the scientific
journals but quite unsuitable being one OF tech-
nical nature tor dScssion III ppUc 80 b %
| ton must henceforth be discussed By those VINO IN
full possession Of the facts capable OF Judging.
THE SUPPOSED THERMOpHE.
| AS regards my heat measurer: soon after my
paper to the Royal Society, requiring some glass
! tube and not finding it, used quill pen which
bappened TO be on the table; | foun1 the quill
Every sensitive to heat, and some friends and jour-
nalists visiting me soon after l showed them the
remarkable senstiyeness of this ordinary quill to
heat. The Engiaee and Electrician, owing to
nv hurried explanation. having so many
| moro important experiments to show, thought
the effects were due as a thermOpile, and gave it
| nm notice prominence IL did not require Thought
then and think still that the matter was or no pTac-
teal Importance as we have already such excellent
and sensitive heat measureTs each suitable for some
special experiments. Mine has long since gone in
~, ,vast, eyneTiment box and if Mr. Edison has
| made n very similar one, and thinks IL OF value
he is welcome to his own and mine too, and should
recommend him to try quill IN place Oh the Nulca-
mite have lately seen described
TIE CHARGES AGAINST MR.. PREEcE.
Mr.. Edison has made publicly gross personal
| attack upon the honor of Mr.. Preece and myself,
and this part he must prove as publicly as he has
made 1t, or stand confessed wlful slanderer his
message to Sir w. Thomson, London, says:
Edison 10 Sir W. Thomson Direct impact carbon
teephoue sent months ago. also publications.
ana letters describing its as heat measnrer great
aDuse confidence, his part in Hughess matter-l send
| YOU publication Of proofs.
This message seems carefully worded, although it
| ;nsinuates an abuse OF confidence on Mr. Freezes
mart. The carbon telephone received through his
agent, Mr., Adams, two months since, have already
mentioned but had already shown mine some
weeks before its arrival at the Post Office, and had