First Glass Insulator Used on Telegraph Line in 1827 on Long Island, NY

DR. O'SHAUGHNESSY AND ELECTRICAL WIRES.

To the Editor of the Mechanics' Magazine.

SIR,—In a letter published by Dr. W. B. O'Shaughnessy, of the Hon. E.I.C., in the Times of Friday last (11th), he therein declares himself the inventor of "Overground Telegraph Conductors" in the year 1839.

In 1746, Winkler, at Leipsic, had telegraphic communication in connection with a long wire.—3 Annuls of Eke., 445.

In 1748, Watson did the same, on an extended circuit of four miles.—Ib. 445.

In 1784 or 1787, Loneard did the same on a wire from room to room. — Vail's Hist., 121.

In 1798, Betancourt sent electricity a distance of twenty-six miles.

Same year, Salva, at Madrid, worked many miles of telegraph.—3 Annals of Elec., 446 ; Vail's Hist., 121.

In 1807, Soemering, at Munich, erected a galvanic telegraph.—3 Annals of Elec., 448.

In 1816, Ronalds, at Hammersmith, operated a telegraph, with clocks, eight miles. —Ib. 449.

In 1827, Harrison G. Dyer constructed a telegraph on Long Island, State of New York, America, at the race-course, by wires on poles, using glass insulators.—(See Evidence in case of T. O. I. Smith v. Hugh Downing et al., District Massachusetts; May term, 1850.)

In 1837, Steinheil "had at the Royal Observatory" an "electric magnetic telegraph," half a mile long, on poles.

Yet, two years after this last, Dr. O'Shaughnessy dates his (so called) invention. Comment is needless; the public, at all events, should be put right on this matter.

JOHN W. WILKINS.

5, South-square, Gray's-inn.