Insulator Historical Timeline! 1860-1869

Key events are noted by approximate date.  Hyperlinks will provide additional information.  Please feedback additional key dates or note any needed corrections.  Dates considered particularly significant are highlighted in red.

• October 24, 1861: The Transcontinental Telegraph, which connected St. Joseph, Missouri and Sacramento, was completed by the Western Union Telegraph Co. and its associates.  (Also see 1869 below).
• November 30, 1863:  Ralph Gray died, leaving Robert Hemingray as the administrator of his will.  Click here for more details.
• 1864: James Brookfield hired to operate the Bushwick Glass Works in Williamsburgh, NY.
• November 29, 1864:  David Brooks of Philadelphia, PA patent for a metal and glass ramshorn insulator.  (US Patent 45,221) -- [Full Patent Text]
• April 4, 1865:  S.F. Van Choate of New York, NY patent for an unusual ramshorn insulator and mounting bracket design.  (US Patent 47,141) -- [Full Patent Text]
• July 25, 1865:  This important patent was by Louis Cauvet for the a method of forming internal threads an insulators to allow them to screw onto a threaded pin.  Previous insulators were threadless and held on the pin by friction. Brookfield was the first to license this patent.  (US Patent 48,906) -- [Full Patent Text]
• July 27, 1866:  Another trans-Atlantic cable was laid with minimum problems.  The length of this cable was about 1680 miles.  The initial rates to use that cable were about $1.00 a letter!  This was a large sum in the mid 1800's.  The success of this cable halted efforts on the Collins Overland Telegraph line which was attempting to connect North America with Europe with a land line up through Alaska, a short cable across the Bering Straight into Russia where a 7000 mile overland line would connect with Europe!  Much great threadless glass was used on the completed portion of this line including Chester and Tillotson hats.  There are rumors that a cache of these insulators may have been abandoned in Russia for the European end of the line!
• March 26, 1867: David Brooks of Philadelphia, PA patent for a metal encased rams horn style insulator.  (US Patent 63,206) -- [Full Patent Text].
• May 14, 1867:  George Floyd of Cincinnati, OH patent for a threadless locking pintype insulator.  This attribute was implemented on on an early Hemingray style of CD 732.2, three of which were found in association with a lightning rod set-up in Cincinnato, OH.  (US Patent 64,654) -- [Full Patent Text]
• June 25, 1867:  Darius Stebbins of Wallingford, CT patent for a lightning rod insulator design.  (US Patent 66,054) -- [Full Patent Text]
• August 6, 1867:  Reissue of David Brooks 1864 ramshorn insulator patent.  Many of the Brooks Ramshorns are marked with this patent date.  (US Patent Reissue 2,717)
• October 8, 1867: David Brooks of Philadelphia, PA patent for a metal and glass ramshorn insulator.  (US Patent 69,622) -- [Full Patent Text]
• October 22, 1867:  John L. Waite of Burlington, Iowa patent for a metal and insulating material ramshorn insulator design.  (US Patent 70,052) -- [Full Patent Text]
• October 22, 1867: Daniel W. Teller and William Savage patent for a two piece glass block style insulator.  I am not aware of any specimens matching this patent being found. (US Patent 70,132) -- [Full Patent Text]
• November 12, 1867:  Thomas J. Lockhart and Josiah Locke of Pittsburg, PA patent for a  lightning rod insulator bracket.  (US Patent 70,727) -- [Full Patent Text]
• November 26, 1867: Merritt L. Wood of Ithaca, NY patent for a cast iron telegraph insulator. (US Patent 71,564) -- [Full Patent Text]
• December 17, 1867: Homer Brooke made molds lettered TILLOTSON & other items for Tillotson & Co -- Follow this link for additional Homer Brooke information.
• March 24, 1868: Cromwell Varley of New York, N.Y. (Citizen of Great Britain) patent for an improvement in insulator pin preparation.  (US Patent 75,815) -- [Full Patent Text]
• July 1868:  Robert Hemingray successfully constructed and operated a glass press to form threads in glass insulators.  (Statement to Commissioner of Patents reported in Official Gazette of the U. S. Patent Office, 22 July 1873).  The style of the insulator first manufactured by this process would have been un-embossed variants of CD 127.4 or CD 131.4.   Manufacture of un-embossed threaded insulators continued until the Dec 19, 1871 Patent was awarded and the molds were modified to include the patent date (most likely early in January, 1872).
• 1869: James Brookfield purchases the Bushwick Glass Works.  It is not exactly known when the name changed to the Brookfield Glass Co.
• 1869:  The Transcontinental Telegraph, which connected St. Joseph, Missouri and Sacramento, and completed by the Western Union Telegraph Co was rerouted to follow the Transcontinental Rail Road.
• October 26, 1869:  Charles Bush of New London, CT patent for a rubber liner for a threadless pin to improve the insulating value.  (US Patent 96,198) -- [Full Patent Text]
• November 30, 1869: Alfred G. Safford of St. Albans, VT patent for an insulator with a cap to protect from moisture.  (US Patent 97,318) -- [Full Patent Text]

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