The Stourbridge Observer, Cradley Heath, Halesowen & District Chronicle.
Stourbridge, West Midlands, England, 1879-09-13 00:00:00

The EDISON TELEPHONE in LONDON.

We make the following extracts from a very interesting
article in The Times of Monday, describing the practical
application of the Edison Telephone in London :
- • •

_ _
" Telephonic intercommunication on a practical
working scale has at length become an accomplished
fact in the City of London, as was demonstrated on
Saturday last by means of the Edison lond•speaking
telephone to a nurrher of scientific gentlemen and
others connected with this exceedingly interesting ques-
tion, both as regards its scientific and commercial
aspects. It has for long past been well known that
this method of communication is extensively practised
in the United States, where the system has taken firm
root. And it has also been equally well known that
endeavours have rocently been made to establish a
similar system in England. Saturday witnessed the
achievement of this object with the Edison telephone,
when what will probably prove to be but the first instal-
ment of a widespread system of public service was suc-
cessfully inaugurated. The peculiarity of this tele-
phone is that the diaphragm of the receiving instru-
ment is set in vibration by a process altogether differ-
ent from that which obtains in any other telephonic
system or instrument. The present very perfect
apparatus is due primarily to the fact that during
some experimental researches in 1872 Mr. Edison made
the discovery that when a
.strip of paper moistened
with &chemical solution which was readily decomposed
when a current of electricity was passed through it
was subjected to the action of the electric current, its
surface became smoother. When, however, the
current was withdrawn the paper regained its
normal character, and was comparatively rough.
From this it followed that if the paper was
drawn with a uniform tractive force over a
metal base, having connection with one pole of a
galvanic battery and a strip of platinum foil or wire
connected with the other pole was pressed on the paper,
the latter would slip whenever an electrical current
was transmitted. lipon the eurrent ceasing to flow,
however, the travel of tne paper would be retarded by
frictional resisistance. Here, then, was the means of
putting in motion matter at a distance by means of elec-
tricity without the intervention of an electro-magnet
This new principle, therefore, supplied Mr. Edison with
substitute for the electromagnet in all forme of tele-
graph instruments, and he was not slow to avail him-
self of the advantages presented by his discovery in
various practical directions in telegraphy. He at once
applied the principle to the construction of a tele-
graphic relay; instrument, in which he entirely dis-
pensed with the use of electro magnets."

The Times then gives a description of the mechanical
arrangements by which sounds are conveyed and reproduced
and proceeds :
- -

"The instrument is so arranged that a conversation
can be maintained between two persons at a distance
without the slighest personal inconvenience or cliff-
culty, the transmitting part of the apparatus being
placed conveniently for the mouth and the receiving
portion in a line with the ear. The practical applica-
tion of the system at present extends to ten stations,
all placed in connection with a central station called
the Telephone Exchange, which is situated in Lom-
bard-street. The stations, or more properly speaking
the private offices, which are connected with the
exchange are situated—No. 1 in Copthall-bnild-
ings, No. 2 in Old Broad-street, No. 3 in Suffolk.
lane, No. 4, in Lombard street, No. 5, in Princes-
street, No, 6 in Carey-street, Lincoln's-inn, No.
7 in Queen Victoria-street (the offices of the com-
pany), No. 8 in George yard, Lombard-street,
No. 9 in Throgmorton street, No. 10 being our own
establishment. At the central office there is a switch-
board capable of being connected with twenty-four
different stations, but which at present is only con.
fleeted with the ten we have mentioned. The number
twenty-four is the most that can be attended to by one
person, but there may be any number of switch boards
in the same room, and any station on one board can be
connected with any one on another board. Adjoin-
ing the switch-board is a telephonic apparatus. and
the operator—who may be a boy—sits in front of the
board. Assuming that station No. 2 wishes to com-
municate with No. 6, the person at No. 2 calls the
attention of the attendant at the exchange by means
of an electric bell. At the same moment a shutter on
the switch-board falls and discloses the number of the
applicant. The attendant acknowledges the signal,
and No. 2 instantly says, "Connect me with No, 6."
The shifting of a pin effects this, and Nos. 2 and 6
are left to communicate with each other. At the close
of the conversation No. 2 gives a signal on the bell to
intimate that he has finished, and the attendant with-
draws the pin and No. 2 and 6 are instantly separated.
And so with any other numbers ; they can be instantly
connected or disconnected, and any number of stations
can be connected up in cLuples and worked at the same
time. Of course, only oae station can be connected
with one other at the same time ; but the coupling and
the uncoupling are affected so quickly that a person
may communicate with asp others in very rapid suc-
cession.
" The practical success of all these arrangements
must depend very largely upon the possession of a
means of communication vbich meets certain every-
day requirements. In other words, it means that the
transmitting instruments employed must be able to
strsm
oa clearly,co ntin ge
rsno
y o
d eitherth o receivingin oud
partytone,
a
being a short distance from his instrument, or in a low
tone, so as to enable a conversation to be carried
lls to it
moot3me" thea geB
on which may be audible te the receiving party, but
inaudible to others who may be near and whose
ears it is desirable that the conversation shall not
reach, These necessary conditions were shown to
be amply present, with many others, in the Edison
loud-speaking telephone on aaturday, the working
being in charge of Mr. E. H. Johnson, the engineer,
and Mr. Arnold White, the manager, of the company.
Loud-speaking this telephone certainly is, but it is
none the less soft-speaking also, for conversations
were carried on between two parties in whispers, and
although a low hissing sound was perceptible to the by-
standers, they were unable to catch the words of the
speaker at the distant station. On the other hand,
words spoken in a loud tone were audible even
at times above the hum of conversation. A great
many tests were applied by those present in
order to prove the system in various whys. but
In no case was there any failure, although at some'
of the stations the operators were spite fresh at the
work, and in one or two instances were possessed of
rather weak voices. Communications were opened,
maintained, and closed with the various stations in
rapid succession, including our own, and with every
success. And here we may mention that a paragraph
was recently set in type in our office whieli was
dictated through the telephone, the result being a per-
fectly correct reproduction of the transmitted subject.
"It wiU thus be seen that this latest and most im-
portant outcome of Mr. Edison's scientific researches
has so far proyod Wolf to bo a praotioal IMMO in this

country. Its future development will of course be
governed by the demand for this methid of communi-
cation, and although there may not be so large a scope
for it in London and some of the provinces as in the
cities of the United States, there is still a wide field
for its application, more especially perhaps in country
towns and outlying districts. With regard to the
distance at which communication can be maintained
without difficulty by means of the telephone, it
is stated that it has been worked between, stations
100 miles apart in America. Shorter distances, how-
ever, are considered to be better than long ones for
perfect transmission, and as a rule it may be taken
that there is no loss of power up to about five miles'
distance. Beyond that point there is a perceptible
loss, which goes on increasing with the distance. But
in practice even five miles will no doubt be found to
be an exceptional distance and would perhaps only
be met with where two stations were each two miles
and a half from the central exchange. At any rate,
so far as present requirements are concerned, the
apparatus as now arranged appears to fulfil all the con-
ditions and requirements of practice, and, while we
congratulate its inventor upon its success, we may
anticipate its widespread application."