细节
HARRISON, JOHN and JOHN MASKELYNE. 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. Clark for J. Nourse and Mount & Page 1767 (Edited by Nevil Maskelyne). 4to, 262 x 198mm. (10 5/16 x 7 13/16in.), modern red morocco in eighteenth-century style, covers gilt-and blind-panelled, spine gilt. FIRST EDITION. 10 folding engraved plates. Grolier/Horblit 42b; Norman 995.
The Board of Longitude offered a reward of £20,000 in 1714 to anyone who could accurately determine longitude at sea. Harrison, a clockmaker, son of a carpenter and with little formal education, rose to the challenge by constructing a working model of his "time-keeper" in 1735 and refined it successively in 1739, 1749 and 1759, testing each model himself, or with the help of his son William, on ocean voyages. Payment of the reward money was made conditional upon publication of an explanation of the invention, and Harrison's inability to express himself in writing led him into an association with Nevil Maskelyne, the astronomer-royal who was appointed with six experts to form a panel of judges by the Board of Longitude. Harrison argued with Maskelyne that the latter was so intent on making use of lunar tables as to disregard his mechanical inventions. From 1737, when he received £500 of the reward, until 1765, Harrison's skill was recompensed by various instalment payments, leading up to the publication of the Principles in 1766. It was not until 14 June 1773, after he had constructed a fifth watch the previous year, that Parliament granted him the remaining £8,570 of the reward, at the direct intervention of King George III.
The Board of Longitude offered a reward of £20,000 in 1714 to anyone who could accurately determine longitude at sea. Harrison, a clockmaker, son of a carpenter and with little formal education, rose to the challenge by constructing a working model of his "time-keeper" in 1735 and refined it successively in 1739, 1749 and 1759, testing each model himself, or with the help of his son William, on ocean voyages. Payment of the reward money was made conditional upon publication of an explanation of the invention, and Harrison's inability to express himself in writing led him into an association with Nevil Maskelyne, the astronomer-royal who was appointed with six experts to form a panel of judges by the Board of Longitude. Harrison argued with Maskelyne that the latter was so intent on making use of lunar tables as to disregard his mechanical inventions. From 1737, when he received £500 of the reward, until 1765, Harrison's skill was recompensed by various instalment payments, leading up to the publication of the Principles in 1766. It was not until 14 June 1773, after he had constructed a fifth watch the previous year, that Parliament granted him the remaining £8,570 of the reward, at the direct intervention of King George III.