Dyar's Patent and the First Glass Insulator in the United States
by Bob Harding
Reprinted from "Crown Jewels of the Wire", September 1988, page 30
I found the following information in a 1915 book on the telegraph and thought
it was interesting and would like to share it with Crown Jewels readers.
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In almost every grade school in America, Samuel Morse is given credit for the
first working telegraph in the U.S. Sixteen years earlier in 1828, an inventor,
Harrison Gray Dyar, constructed and demonstrated a working telegraph on Long
Island. Dyar's telegraph used strokes of electricity to make sparks. These
sparks acted upon litmus paper by using a mechanical devise regulated by a
pendulum. The sparks caused the formation of nitric acid which caused red marks
on the moistened blue paper. The difference in time between the sparks caused a
variation in the chemically produced images. An arbitrary alphabet was set up to
read the marks.
Dyar's early experimental telegraph line was several miles long. Dyar and a
"Mr. Brown," an investor from Providence, Rhode Island, set up the
first line at the race course on Long Island. They obtained some fine card wire
and ran it around the race course several times. They set up the wire at
different lengths, in curves and straight lines, by suspending it from stake to
stake and tree to tree using glass insulators.
After setting up this first telegraph line, they decided that the experiments
justified running a line from New York to Philadelphia. At this point their
agent filed suit against Dyar for $20,000 for agencies and services, which Dyar
found was done to extort a concession of a share in the project. After losing
that battle, the unscrupulous agent obtained a writ against the two partners on
a charge of conspiracy to carry on secret communications between the two cities.
This accusation eventually put an end to the project without the formality of
judicial trial.
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What happened to the experimental insulators is a mystery. Were they left
attached to the trees around the race track, or salvaged for the planned New
York to Philadelphia line? We probably will never find out or even get a look at
this insulator. Shouldn't Dyar really be listed first? By the way, if anyone
digs one of these up, I'd love to hear about it.
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