The record-union., 1894-07-14
MARSHALLS MAGIC BOOK.
1t Spoke as Though it were a
Human Being.
New Principle In Telephony-You Can
Hear What This Receiver Has TO
say If Standing Twenty Feet Away
How it is Accomplished.

connected with the telegraphic or electric
businesses were assembled in room in
the eleventh story of the new Postal
Building. in Broadway, opposite the City
Hall Park. They had not been there very
long when astonishment was depicted on
their faces and by and by found express
sion in words.
A book on the table about which they
stood or sat was speaking.
''Is it possible" exclaimed Mr.. Chand-
Ter, of the Commercial Cable Company,
''that those spoken words can come from
that book?"
Eyes. it is" said Francis w. Jones.
the electrician of the company; ''that is
Mr.. Marshalps telephone"
William Marshall, of No. 700 Lexing
ton avenue, had prepared this remarkable
feat for the electricians. He began by
taking up an ordinary book and placing
in the leaves several slips of tinfoii, about
one and half inches wide and four
inches long. Then he attached a couple
of fine wires, closed the book and carried
the other end of the wires to another
room, where they were attached to the
transmitter of telephone. Then a con-
versation began, with Mr.. Marshall in
one room and one of the persons in the
room where the book lay. Each word
that came from the book could be dis
tinctly heard in every corner of the
room.
ITS NEW PRINCIPLE.
The visitors had never experienced
anything of the kind before, and they
said it would eventually revolutionize
telegraphy.
tested the Marshall telephone in Mr..
MarshalPs house in Lexington avenue.
Anyone who has tried to talk over the
wires" on the ordinary instrument knows
the trouble it is to hear and make ones
self heard. This invention of Mr..
MarshalPs does away with the painful
"Hullosp' in which so much time is
wasted.
The new principle Is the direct opposite
of the Bell principle. The latter is the
magnetic receiver; the new electro-static.
As described by Mr.. Marshall the inven-
ton consists essentially in telephenic
system, comprising speaking condensers
and an induction coil at each station,
each induction coil having two secondary
wires and primary wire, the opposite
ends of each secondary wire being con-
nected with the opposite poles of the
speaking condensers.
Mr.. Marshalps speciality is electric
condensers, and it was while striving to
improve that that he discovered about
ten years ago the new principle. The
book which l saw, or rather 'heard,"
in his house was q common catalogue.
He had placed in the leaves eighteen
pieces of tinfoil, about two inches wide
and five inches long. To this wires were
connected alternately with the tinfoil.
Against the wall was an ordinary trans
mitter.
The book, with the wires attached, de-
pended from the wall. Mr.. Marshall
went up stairs. l took up the book to
examine it more closely.
How are your" was the question from
the book. | closed the leaves, but that
made no difference, for the next question
the catalogue asked was:
AS THOUGH By ENoHANTMENT.
DO you think it will rain to-mor-
row7''
was too much astonished to answer,
and the book, which appeared to me for
the time to be human, may have noticed
it. because it began to whistle, as if to
give me time to collect my thoughts.
Then / went up to the transmitter and
inquired-"Can you sing?"
mo, am not much of singer,u came
from the neighborhood of my boots. l
had dropped the book and 1t nearly
touched the floor. / went into corner
of the room. and still l heard the book
talking distinctly. l squeezed and bent
it, but that made no dlfference-it con-
tinued to talk just the same.
When Mr.. Marshall returned to the
room he showed me another modification
of his invention which he said cost only
five cents TO make. Outwardly il was the
size of small circular hand mirror. The
circular part contained annular rings of
paper and tinfoil, the outer rim only OF
tinfon, being compressed, the inner
ring being free to vibrsts. This was
connected with wires in the same way as
the book.
Mr.. Marshall went up stairs again, and
/ remained In the parlor with the mirror
like thing in my hand. Presently I
heard Mr.. Marshall's voice coming from
it. l held it at arms length, and still the
sounds were distinct. far more so than
those coming from any telephone had
ever used. When / put it to my ear it
was as If the person speaking were at my
shoulder talking loudly.
Mr.. Marshall said that distance would
make no difference in the distinctness of
the sound. The principle would do away
with the receiving instrument of the tel
egrapher. With such condenser lying
on his desk he could write his message
without fear of mistake. The inventor
calls his a telephone system with speak
ing condensers, in which more perfect
transmission OF the volume of speech can
be accomplished than has been possible
heretofore in systems of this kind.
WITH A LINE WIRE.
Mr.. Marshall said that In his receiving
speaking condenser telephone the oppo-
site poles are connected with line wire
and a shunt or resistance coil.
He discovered that unless the line wire
connecting the stations is made continu-
Gus, as by shunting the speaking con-
denser, the articulation and volums of
speech are not perfect, being scarcely au-
dible when more than one speaking con-
denser is inserted in the line of commu-
nication.
The condensers speak much louder
when the metallic plates are in part. not
touching or in contact with the insulator,
allowing q space sufficient to vibrate
freely, and to impart to the air the sound
which is transmitted from distant sta
ton so as TO be easily heard. The speak
ing condenser is built up in the same
manner as if the leaves of slectrometers
were intersected into each other, one end
of the plates only being fastened.
In what have described as the s'hand
mirror receiver the middle of the plates
are made loose by pressing the circum-
terence together, the plates and insulaters
bulging sufficiently in the center to sepa-
rate themselves.
Mr. Marshaps house is filed with the
latest standards and testing apparatus,
and enabling him TO produce the most
accurate instruments, which have made
his name famous among electricians
New York Herald.