“Herschel, with ample mind and magic glass,
Mid worlds and worlds revolving as they pass,
Pours the full cluster’d radiance from on high,
That fathomless abyss of Deity.”
Purs. of Lit. dial. the fourth.
[86]. Philip III. king of Spain, first offered a reward for the discovery of the longitude, about two centuries ago; and the States of Holland, soon after, followed his example. The Regent of France, during the minority of Louis XV. also promised a great reward to any person who should discover the longitude at sea.
In the year 1714, the parliament of Great Britain offered a reward for a like discovery; and if the method, to be proposed, should determine the longitude to twenty geographical miles, the premium was to be twenty-thousand pounds sterling. The act of parliament established a board of Commissioners of the Longitude. Several other acts were passed, in the reigns of Geo. II. and III. directed to the same purpose. Finally, in the year 1774, all those acts were repealed, by one offering separate premiums for finding the longitude; either by the lunar method, or by a watch keeping true time,—or by any other method practicable at sea. This act proposes as a reward for a time-keeper, 5000l., if it determine the longitude to one degree or sixty geographical miles,—7500l., if to forty miles,—and 10,000l., if to thirty miles. If the method be by improved Solar and Lunar Tables, constructed upon Sir Isaac Newton’s theory of gravitation, the author is to receive 5000l.; provided such Tables shall show the distance of the Moon from the Sun and Stars within fifteen seconds of a degree, answering to about seven minutes of longitude, after making an allowance of a half a degree for the errors of observation. The Commissioners have the power of giving smaller rewards, at their discretion, to persons making any discovery for finding the longitude at sea, though it may not be within the above limits.
The set of Solar and Lunar Tables which were sent to the Board of Longitude, about the year 1763, by the widow of the celebrated astronomer, Tobias Mayer, were honoured with a reward of 3000l. sterling, by an act of the British parliament, in consideration of their great usefulness in finding the longitude at sea.
[87]. See Mr. de Zach’s great work, entitled, Tabulæ Motuum Solis novæ et correctæ, &c.
[88]. For the use of such readers as may not be acquainted with the Latin language, the following translation of the above is given, from the original of Mr. de Zach.