HARRISON, John (1693-1776) [and Nevil MASKELYNE (1732-1811)]. The Principles of Mr. Harrison's Time-Keeper, with Plates of the Same. Published by Order of the Commissioners of Longitude. London: W. Richardson and S. Clarke for John Nourse and Mess. Mount and Page, 1767.
Oblong 4o (266 x 213 mm). 10 engraved plates (one folding) (some light spotting). (Lacking half-title, some spotting.) Contemporary tree calf (rebacked to style); quarter morocco folding box. Provenance: Strickland Freeman, Esq. (1781-1821), Ecquinologist (bookplate); Otto Orren Fisher (bookplate).
"THE DESCRIPTION OF THE FAMOUS SOLUTION TO THE CENTURIES-OLD WORLD-WIDE PROBLEM OF FINDING THE LONGITUDE" (Grolier/Horblit)
FIRST EDITION. In 1714 the Board of Longitude offered a reward of £20,000, an impressive sum of money at the time, to anyone who could find a reliable and accurate method for determining longitude at sea. In 1730 the clockmaker John Harrison completed a manuscript describing some of his chronometrical inventions, including a chronometer "accurate enough to measure time at a steady rate over long periods, thus permitting the measurement of longitude by comparison of local solar time with an established standard time" (Norman). On the strength of his descriptions, Harrison obtained a loan from George Graham, a leading maker of clocks and watches, for the construction of his timekeeper.
After numerous attempts, involving instruments in several different shapes and sizes, most of which either Harrison himself or his son William tested on ocean voyages, Harrison succeeded in constructing a chronometer that was both accurate and convenient in size, which was successfully tested on two voyages to the West Indies in 1761 and 1764. After the successful trial of his first device in 1737, the Board of Longitude had encouraged him with a grant of £500, and had begrudgingly followed this up with more small payments over the years. Following the two successful trials of his fourth and best instrument, Harrison felt that he had a right to the prize, but the Board of Longitude hedged, insisting on a demonstration and full written description of his invention. The demonstration took place on 22 August 1765, in the presence of the astronomer-royal Nevil Maskelyne and a six-member committee of experts appointed by the Board.
The results were written up and published in this pamphlet by Maskelyne, along with Harrison's own description of his timekeeper. Still unsatisfied, the Board awarded Harrison only half the prize money, and continued to raise obstacles, subjecting his chronometer to extreme and unrealistic tests, and requiring him to build yet two more examples. It was not until 1773, after direct intervention by King George III, that the 80-year old inventor was paid the remainder of the prize money, His four earliest chronometers are preserved at the Royal Observatory in Greenwich. Although it was soon supplanted by simpler mechanisms, Harrison's timekeeper "revolutionized the science of navigation, as it gave navigators their first means of observing true geographical position at any given moment during a voyage. There was no comparable advance in navigational aids until the development of radar in the twentieth century" (Norman). Grolier/Horblit 42b; Norman 995.
MASKELYNE, Nevil. An Account of the Going of Mr. John Harrison's Watch, at the Royal Observatory, from May 6th, 1766, to March 4th, 1767. Together with Observations and Calculations of the Same... Published by Order of the Commissioners of Longitude. London: W. Richardson and S. Clark, 1767. 4o. (One or two spots.) Recording the predictably disappointing results of Maskelyne's series of extreme and unrealistic tests: "Mr. Harrison's watch cannot be depended upon to keep the longitude within a degree in a West India voyage of six weeks... nevertheless, that it is a useful and valuable invention, and, in conjunction with the observations of the distance of the moon from the sun and fixed stars, may be of considerable advantage to navigation" (Maskelyne, p. 24). Norman 997.