New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1877-03-31
THE SOUNDING BOX RECEIVER.

y, -
rent from a main battery is required. The Gray
sending instrument is in outward shape piano OF
two octaves The tune to be transmitted must be
played on the keys of this piano. Each key has ITS
own tuning fork, and when key is depressed part
of the electric current that travels through the main
line is diverted that it goes through that particu
lar tuning fork. The mechanism by which the cleo
trio current is thus switched on and OF the line
BY touch to a piano key is somewhat complex,
and its details would not be of interest to the
general reader. The receiving instrument is an
electromagnetic, X X, mounted by one of its coils
and a support, j. upon sounding box, l.. The
prong of a tuning fork, NJ, approaches very nearly
but does not quite touch one pole of the magnet;
the handle of the fork is connected with the other
pole through the support J. When the apparatus is
thus arranged there must of course be a separate
sounding box for every note that the telephone
transmits.
CAPABIIITY OF THE MUSICAL TELEGRAPH.
By using in the sending apparatus in addition to
the main current current from smaller, special bat
teres one for each note. Mr.. Gray has achieved a
further improvement. BY this the intensity of mu
steal note Is given as well the note itself. Chords
of two or three notes can also be transmitted. Ii
will be that the receiving tuning fork selects
out from the main current the electrical impulses or
the making and breaking of the current, which cor
respond to its own vibration. Hence receiving
tuning fork will only sound when a sending tuning
fork of the same note or pitch is transmitting. The
practical which is claimed for this is that by 1t
several messages of the ordinary Morse signals may
be sent from central office over single line, and
no one of them will be repeated at any station
except the one for which each message is designed.
as every station will have a receiving instrument
that sounds to different note from the others, and
the operator at the central Office taps for each on
different key. Although the current for the note or
pitch is intermittent. its pulsatiOns are rapid
several hundred in a secOnd) that for telegraphing
purposes it may he regarded as continuous current.
The Morse signals make and break this intermittent
current just they would an ordinary one. The
receiving operator hears the message in the make
and break of Morse signals from his sounding box.
In one of the more recent designs for his telephone,
Mr.. Gray proposes to put diaphragm or membrane
in front of the opening of the sounding box to catch
the vibrations and communicate them 10 a printing
machine, which in turn will print the message in
Morse signals or telegraphc tape.
A COMPARISON OF TELEPHONES.
1t will be seen that the difference between these
telephones is very great. The GRAY telephone
operates by means of tuning forks and the signals
are sent by a make-and-breal system as Geographic
signals usually are. In the Bell telephone the cur
rent is not "shuutcd" switched: there is nothing
done on the make-ani-brcak system either as 10
vibrations or signals; and finally, the vibrations
arc the signals. From these radical differences it
results also that the Gray telephone can only trans
NIT two of the three characteristics Of musical
sound e., pitch and intensity, but not quality. SO
long as the vibration must be transmitted through
tuning forks, the Gray telephone can never trans
nit what Helmhotz has called the OyertOnes."
These are weaker harmonic notes which accompany
tine primary tone and differ for each musical in
strument; they make the variety TO our ears of
quality Of sound by which we distinguish, for in
stance between the notes Of flute and of violin.
These overtones are not given by tuning forks and
cannot be- On the other hand, no matter what may
be the hight ength, frequency of the sound waves
that strike the stretched membrane in the Bell tele
phone, their exact counterpart in vibration can be
reproduced atthe other end OF the line. But at best
the vibrations in Prof. Bell device only affect
part of the current they may be essentially
feeble, compared with signals on q make-and-brcak
system. If recent accounts are to be trusted, this
defect has been measurably overcome by the use of
ongerelectro-magnet. Perhaps the harmony which
both inventors DESTROYS of mastering may extend
from sound to sense and the two telephones may
day work literally in concert. When that is done it
may be practicable to set up sOund-bOard behind an
orchestra and telegraph its whole performance to
distant city. Meanwhile the public will have plenty
of time to form opinion on the comparative merits
of the Instruments ana to recover from the present
confusion Of ideas which was so admirably exempli-
fled at Philadelphia by inquiries made in the Main
Building for "the talking machine of Bellham
Gray"