ON THE HISTORY OF ASTRONOMY. 461 



their number : he showed the disadvantages of the method proposed hy 

 Mr. St. Pierre, and the inaccuracy of the existing tables of the lunar 

 motions, as well as of the catalogues of the places of the stars, but expressed 

 his opinion, that, if the tables were improved, it would be possible to deter- 

 mine the longitudes of places with sufficient accuracy by lunar observations. 

 The king, being informed of Flamsteed's representations, is said to have 

 replied with earnestness, that he " must have the places of the stars anew 

 observed, examined, and corrected, for the use of his seamen ;" upon this 

 Flamsteed was appointed Astronomer Royal, with a salary of 100 a year, 

 and it was proposed to have an observatory built either in Hyde Park, or 

 at Chelsea college ; but, upon Sir Christopher Wren's recommendation, 

 the situation of Greenwich Park was preferred. 



In the year 1714, the British Parliament offered 20,000 for a determi- 

 nation of the longitude of a ship at sea, without an error of 30 miles, and 

 a smaller sum for a less accurate method, appointing at the same time a 

 Board of Longitude for the examination of the methods which might be 

 proposed. Under this act several rewards were assigned, and in 1774, it 

 was superseded by another, which offers 5000 for the invention of any 

 timekeeper, or other method, capable of determining the longitude of a 

 place within one degree, and 10,000 if within 30 miles ; and a reward of 

 5000 to the author of any lunar tables, which should be found within 15 

 seconds of the truth ; allowing the Board also the power of granting smaller 

 sums at their discretion. Timekeepers are at present very commonly em- 

 ployed in the British navy, and some of them have been capable of deter- 

 mining the longitude within half a degree, after having been two or three 

 months at sea. The lunar tables, which have been employed for the 

 Nautical Almanacs, are those of Professor Mayer, who adopted the methods 

 of calculation invented by Leonard Euler ; but the tables of Mr. Burg, of 

 Vienna, are still more accurate, and are said to be always within about ten 

 seconds of the truth. 



The progress of astronomy, since the death of Newton, in 1727, has been 

 fully adequate to what its most sanguine votaries could have hoped. The 

 great discoveries of the aberration of the fixed stars, and of the nutation 

 of the earth's axis, were made by our countryman Bradley, with the 

 assistance of the instruments for which he was indebted to the delicate 

 workmanship of our artists. Among these the names of Bird, Short, 

 Sisson, Graham, Dollond, Harrison, and Ramsden have long been cele- 

 brated throughout Europe. The geographical operations, which have been 

 performed in every part of the globe, have been chiefly conducted by the 

 liberality of the French and English governments, although other countries 

 have not been deficient in taking their share of the labour. Observations 

 of the transit of Venus were made with great care in the south seas 

 by British navigators, whom the munificence of our present sovereign 

 enabled >to undertake so arduous a voyage for this express purpose ; and we 

 are indebted to the fund which was granted on the occasion, as well as to 

 the zeal of the Astronomer Royal, for the experiments on the attraction of 

 mountains, which were instituted after their return. In this country also, 

 Dr. Herschel, besides many other important additions to our astronomical 



