New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1881-10-09
THE ELECTRIC EXHIBITION.

THE CLAIMS OF GRAMME AND PAClNoIlL
LETTER FROM PROFESSOR CARROLL ON HE
RIVAL CLAIMS To THE INVENTION OF THE pf-
NAMo-GENERAToR-TEsTLM OF PROFESSOR
NEUTRALITY-SUSPICIOUS. or THE TWO MA
CHIMES.
TO he Edf Of The Tribune.
SIR: In INV correspondence with you on the Elec-
trio Exhibition, had made mention OF the niue
machine on view IN the Italian Department known
as the Pacinotti dynamo generator. Its presence
al the Exhibition has excited general interest aau
discussion from the fact that it seems to prehgnre
later invention, the Grammc arnature, which mas
carried magnetic electricity from its former state Of
al experimental science into the ranks OF the pFac-
teal arts. At the suggestion Of friends was in
duced 10 suppress the paragraph, as likely to lead
to unfair conclusions Respecting the mer''s OF the
later inventor. NJ. Gramme. At the san sngges-
ton beg to offer to your indulgence brief sum-
mary of the main points in the discussion:
Up to about $50 the machine now known as the
dynamo. electric generator had not advanced beyond
the point of perfection of the old Alliance anna
ture in which n series of gpools of wire, EMBEDDING
each its separate of soft iron. set around
the rim of circular disc, and by its revolution
brought into rapidly successive contact with the
poles of the so.called field magnets. In this form
of armaurc the cores 1t will be observed, were per-
pendicular to the plane of the wheel while the wire
COILS naturally, were wrapped parallel 10 thls
plane In 1860 Professor Pacinott OF Pisa, in
vented new armature. first officially made known
some years after In this form the soft iron core is
continuous a bar of solid metal bent into ring.
and wrapped at intervals with spools or bobbns oil
wire in folds perpendicular to the plane of motion,
and 80 presented to the magnetic poles ia position
at right angles with that Of the old machines.
Scientists recognized in this new form marked
advance in magneto-eectrc science; the machine
was examined discussed. used for experiment. and
fnally-if | am rightly acknowledgement to the
shelves Of the physical cabinet If not actually dis
mounted.
Some years later, NJ. Gramme, then plain,
thoughtful practical mcchanician in Paris. PulltlcsS
of ali knowledge of Italian or Italian scientific
reports struck out his own form of magnetoelecrlc
wheel, which under the name of the Gramme arma-
ture is now known to all enlightened countries. and
lies at the bottom of all present devices for pro-
ducng magnetic electricity. His armature presents
striking features of resemblance with the Paci-
nott in the essential idea while il combines elements
of mechanical detail which immensely increase its
effect and render it practically available for com
mcrcial production. His continuous circular core
is itself bundle of wires not solid bar, and his
enycloping wire coil is continuous. not broken into
separate spools Instead of two extremitics of a
horseshoe bar magnet he surrounds his armaturc
with n series of such magnets arranged pole to pole
in what is called the consequent" form; aud
finally he takes of his current on conmutator or,
more strictly. n collector arranged on principles
widely differing from that OF Pacinotti.
During the discussion aroused by the little Incl
dent above mentioned, ] received from the well
known electrician. Professor Werdermann the fol-
lowing letter of explanation:
LONDON, Sept. 7, 1881.
DEAR SIR: Colonel Hazard has requested ne
to give you some explanation about the difference be
tween the MISUNDERSTANDING ma. ~ ". vihaHnt H
the electro magnetic machine ~ Professor fhclnotu
have great pleasure In giving you the following noFma
ON the 18th Of July ST. Professor Jamn brought he
fore the French Academy Of science thc m "a,
OF August 1871 Professor Pacinott addressed letter
70 the sccrctairc Perpetual Of the french Academy IN
forming the same that I'm 1860 he had constructed for
the physical cabinet OF the University Of Psaa electro
magnetic machine based upon the same principle rs the
Gramme machine But neither the Commission aI-
polntcd ~ the French Academy nor NJ. Grammc took
any notice of Professor PHcnoit- claim. because the
latter not justified In making this claim for the io
Firsay-Professor Paclnotti used in his machine
solid ring Of iron and not ring 90 IRON wire OF oil
several discs fitted together.
Seeondy-Cand this l. the important point Of difference
between the two machine Pacnott coecsthe currents
developed The boDbn AT the ponts the greatest mag
motto intensity, l. e., opposite lEo magnetic pots'
Crnmme ON the contrary, collects the currents do
vclopod in the bobbin at the neutral points.
complete report, but what have pointed out VIII he
sufficient for you TO judge ,.....,,
" Gramme prize Of 5000 francs and IN 1876 the
ChaB,Jre DIES Deputes voted an extraordinary prize OF
20 900 francs for NJ. Gramme the great prize of 10000
francs having been dccrced Ia Mr.. Graham Bell Gramme
also created Cheyaier OF me Legion Of Honor ana
family not have conferred upon him, had hs nyen-
ton not been an original one. remain, dear Sir
f,I, WIuDEKuANN.
10 Professor CARROLL, Paris.
On the morning of my departure from Paris.
September 9, / had brief interview with VI. Grammc
himself ut tie house of is confidential adviser, NJ.
Hippoyte Fontalnc. The points brought out were
in effect such as have stated. NJ. Fontaino urged
with especial emphasis the following heads: In
purely theoretic regards. tho Pacnutti wheel
supplies it is conceded. the idea the scientific germ
of the Gramme immature. But the PaclnottI
machine was a modest little bit of apparatus
about the SIZE of an ordinary kitchen coiiecm'l.
never used for the production Of electric fore,
on the modern commercial footing. and could not
have done 80 even II got up on the most large and
elaborate scale It never passed from the scienifco
experimental TO the practical stage. NJ Gramme.
on the other hand with no inkling of the Pacnotti
idea struck out his own invention. on independent
lines. and promptly developed IL To its present
point of supplying commercial electricity at pay
ing prices TO all the various departments of human
utility in which IL is now employed.
In thus becoming the mouthpece Of views which
no technical claims of my own warrant me IN urging
more positively or infinitely / venture TO hope
have not wcarcd the patience of your readers. IL
is barely possible that this communication may be
of interest to persons specifically Interested IN
science as well TO that large class OF liberal and
alert minds which love justice in all matters OF
PRACTICAL invention, especially IN one which bears so
powerfully on human progress and happiness as the
art of magnetoelecrIcity. Very respectfully yours,
CHARLES CARROLL
NelC- York UniUTstty, Sept. 81, 1851.
4 POINT IN THE STOKES WILL CASE.