<h2><SPAN name="CHAPTER_XVIII" id="CHAPTER_XVIII"></SPAN>CHAPTER XVIII.</h2>
<h3>SHORT-LINE TELEGRAPHS.</h3>
<p>Early in the history of the telegraph short
lines began to be used for private purposes,
and as the Morse code was familiar only to
those who had studied it and were expert operators
on commercial lines, some system had
to be devised that any one with an ordinary
English education could use; as the expense
of employing two Morse operators would be too
great for all ordinary business enterprises.
These short lines are called private lines, and
the instruments used upon them were called
private-line telegraph-instruments. Of course
they are now nearly all superseded by the telephone,
but they are a part of history.</p>
<p>One of the earliest forms of short-line instruments
was called the dial-telegraph. One
of the first inventors, if not the first, of this
form of instrument was Professor Wheatstone
of England, who perfected a dial-telegraph-instrument
about the year 1839. The
receiving-end of this instrument consisted of
a lettered dial-face, under which was clockwork
mechanism and an escape-wheel con<span class="pagenum"><SPAN name="Page_160" id="Page_160"></SPAN></span>trolled
by an electromagnet. Each time the
circuit was opened or closed the wheel would
move forward one step, and each step represented
one of the letters of the alphabet, so
that the wheel, like the type-wheel of a printing
telegraph, had fourteen teeth, each tooth
representing two steps. As the reciprocating
movement of the escapement had a pallet or
check-piece on each side of the wheel, its
movement was arrested twenty-eight times in
each revolution. These twenty-eight steps correspond
to the twenty-six letters of the alphabet,
a dot and a space. On the shaft of the
escape-wheel is fastened a hand or pointer,
which revolves over a dial-face having the
twenty-six letters of the alphabet, also a dot
and space. The pointer was so adjusted that
when the escape-wheel was arrested by one of
the pallets it would stop over a letter, showing
thus, letter by letter, the message which the
sender was spelling out.</p>
<p>The transmitter consisted of a crank with
a knob and a pointer on it, which was mounted
over a dial that was lettered in the same way
as the face of the receiving-instrument. A
revolution of this crank would break and close
the circuit twenty-eight times; that is to say,
there were fourteen breaks and fourteen
closes of the circuit. If now the transmitting-pointer
and the receiving-pointer are unified
so that they both start from the same point on<span class="pagenum"><SPAN name="Page_161" id="Page_161"></SPAN></span>
the dial, and the transmitting-crank is rotated
from left to right, the receiving-pointer
will follow it up to the limit of its speed. In
transmitting a message the sender would turn
his crank, or pointer, to the first letter of the
word he wished to transmit, making a short
pause, and then move on to the next letter, and
so on to the end of the message, making a
short pause on each letter. The end of a word
was indicated by turning the pointer to the
space-mark on the dial. The receiving-operator
would read by the pauses of the needle on
the various letters. This was a system of reading
by sight.</p>
<p>There have been many forms of this dial-telegraph
worked out by different inventors at
different times, and quite a number of them
were used in the old days. It was a slow process
of telegraphing, but it was suited to the
age in which it flourished. One of the difficulties
of a dial-telegraph consisted in the
readiness with which the transmitter and receiver
would get out of unison with each
other; and when this happened of course a
message is unintelligible, and you have to stop
and unify again.</p>
<p>About 1869 the writer invented a dial-telegraph
to obviate this difficulty. In this system
a transmitter and receiver were combined in
one instrument, and instead of a crank there
were buttons arranged around the dial in a<span class="pagenum"><SPAN name="Page_162" id="Page_162"></SPAN></span>
circle, one opposite each letter. When not in
operation the pointers of both instruments
at both stations stood at zero. In the act of
transmitting the operator would depress the
button opposite the letter he wished to indicate,
when immediately the pointers of both
instruments would start up and move automatically,
step by step, until the pointer came
in contact with the stem of the depressed button,
when it would be arrested, and at the
same time cut out the automatic transmitting-mechanism
and cause both needles to remain
stationary during the time the button was depressed.
Upon releasing the button the pointers
both fall back to zero at one leap.</p>
<p>The first private line equipped by this instrument
was for Rockefeller, Andrews &
Flagler, which was the firm name of the parties
who afterward organized the Standard Oil
Company. This line was built between their
office on the public square in Cleveland and
their works over on the Cuyahoga flats.</p>
<p>It seemed, however, to be the fate of the
writer to make new inventions that would
supersede the old ones before they were fairly
brought into use. Very soon after the dial-telegraph
began to be used, printing telegraph
instruments for private-line purposes superseded
them. About 1867 a printing instrument
was devised for stock reporting, which
in one of its forms is still in use. Soon after<span class="pagenum"><SPAN name="Page_163" id="Page_163"></SPAN></span>
the invention of this form of printer a company
was organized to operate not only these
stock-reporting lines, but short lines for all
sorts of private purposes. Following the invention
of the stock-reporting instrument
there were several adaptations made of the
printing telegraph for private-line purposes.
Among others the writer invented one known
as "Gray's automatic printer," a cut and a
description of which may be found on page 684
in "Electricity and Electric Telegraph," by
George B. Prescott, published in 1877. This
instrument was adopted by the Gold and Stock
Telegraph Company as their standard private-line
printer. It was first introduced in the
year 1871, and at the time the telephone began
to be used there were large numbers of these
printers in operation in all of the leading
cities and towns in the United States. While
this has been superseded to a large extent by
the telephone, there are still a few isolated
cases where it is used.</p>
<p>Short lines have multiplied for all sorts of
purposes, until to-day the money invested in
them largely exceeds the amount invested in
the regular commercial telegraphic enterprises.</p>
<p>The invention of the telephone created such
a demand for short-line service that some
scheme had to be devised not only to make
room for the necessary wires, but to so cheapen
the instruments as to bring them within reach<span class="pagenum"><SPAN name="Page_164" id="Page_164"></SPAN></span>
of the ability of the ordinary man of business.</p>
<p>This problem has been solved (but not without
many difficulties) by the inauguration of
what is known as the "central station." By
this system one party simply controls a single
wire from his office or residence to the central
station; here he can have his line connected
with any other wire running into this same
station, by calling the central operator and
asking for the required number. It is useless
to tell the public that very often this number
is "busy," and here is the great drawback to
the central-station system. This is especially
true in large cities, where there are a great
number of lines. The switchboards in large
cities are necessarily very complicated affairs,
and it requires a number of operators to answer
the many calls that are constantly coming
in. Each central-station operator presides over
a certain section of the board, and as this
section has to be related in a certain way to
every other section, it is easy to see wherein
arises the complication.</p>
<p>In large cities the central stations themselves
have to be divided and located in different
districts, being connected by a system
of trunk lines.</p>
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