Calais, Maine

Longitude Determination
Harold E. Nelson
14 Hill Avenue,
Newport, ME 04953

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The significance of the link that the Calais Observatory provided in the chain extending from Harvard University to the Royal Observatory at Greenwich, England, has been compared to the railroad link at Promontory Point, Utah, on May 10, 1869, symbolized by the "Golden Spike."  Note also how close in time these two events occurred. --Richard Auletta -

This is because longitude determination had progressed from Harvard to Calais in 1857. When the ship Great Eastern landed the transatlantic telegraph cable (from Valentia Island, Ireland) at Heart's Content, Newfoundland, the Coast Survey began completing the work eastward from Greenwich to Calais.

The transatlantic work was finished first, but because the cable would not allow a direct connection between the telegraphic equipment, the best that could be done was to place in sync the Krille clock in Ireland with the Kessel Clock in Newfoundland. Also, when the weather was clear in Ireland, it was cloudy in Newfoundland. Finally, observations to determine the longitude difference between Ireland and Newfoundland were finished.

The connection between Newfoundland an Calais also presented problems, and for a while it was doubtful that the men would get the work done. All of a sudden, a 'sharp frost' brought the telegraph lines connecting the two locations, which included a section of sub-marine cable, was brought into near perfect electrical condition.

About December 16, 1866 'east' observations met 'west' observations connecting at Calais, Maine USA.

Another connection, a bit more abstract though, regarding the Golden Spike at Promontory Point is not only did this event connect the east with the west via railroad, but also telegraph. With a telegraph line connection to the west coast, the Coast Survey also pushed their precision longitude determinations via telegraph where George Davidson of the Coast Survey had been mapping the Pacific Coast, improving Davidson's longitude determinations with regards to Greenwich.

Before the transatlantic cable, the commodity of 'world time' was imported to America via precise clocks called chronometers. By 1866, the longitude of Harvard Observatory was based on astronomic observations and 1,056 'chronometer crossings'.

In December 1866, Calais made history by being the port of entry for precise world time. It is important to remember that in all the Coast Survey Annual Reports, longitude west of Greenwich, and also differences between American stations, is given in

hours, minutes, and seconds of time, which have to be converted to Degrees, minutes, and seconds of time.

By 1872, Great Eastern had laid several more cables, including the French Cable from Brest, France.

In 1904, the Coast Survey made the final connections in the Pacific to complete telegraphic longitude differences between stations. When all the pie pieces of arc were added up, the result was within less than one second of a complete circle.

And just prior to this historic world wide longitude determination, wireless telegraphy was coming on the scene where 'time' could be transmitted vast distances by wireless. From there we go on to observatory time signals which were used by the Coast Survey into the late 20th century when GPS came on the scene.


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