82 MASKELYNE. 



* British Mariner's Guide,' the earliest of his separate publications, 

 in which he proposes the adoption of a Nautical Almanac according 

 to the plan indicated by Lacaille, after his voyage to the Cape of 

 Good Hope. In the same year he performed a second voyage to the 

 island of Barbadoes, in order to determine the rates of Harrison's 

 chronometers. In his report on the results of this voyage Maske- 

 lyne, while doing justice to the works of this eminent mechanician, 

 decided in favour of the employment of lunar observations for deter- 

 mining the longitude, strongly supporting the cause of Pro)' 

 Mayer, who had computed lunar tables for this purpose. The 

 liberality of the British Government, however, bestowed on Harrison 

 the whole reward that he claimed,* while Maskelyne, having been 

 appointed to the situation of Astronomer Royal which likewise 

 made him a member of the Board of Longitude, was instrumental 

 in procuring a reward of 5,OOOZ. for the family of Professor Mayer, 

 and a compliment of 300/. for Euler, whose theorems had been em-- 

 ployed in the investigation. 



When the merits of Mayer's tables had been fully established, the 

 Board of Longitude was induced to promote their application to 

 practical purposes by the annual publication of the Nautical Alma- 

 nac, which, during the remainder of his life, was arranged and 

 conducted entirely under Maskelyne's direction. 



Maskelyne held the situation of Astronomer Royal for forty-seven 

 years, during which period he acquired the respect of all Europe, by 

 the diligence and accuracy of his observations, which he always, if 

 possible, conducted in person, requiring the aid of only one 

 assistant. 



Up to Maskelyne's time the observations of the Astronomers 

 Royal had been considered as private property; Flamsted publish- 

 ing his own, while Bradley's were very liberally bought of his 

 family, and afterwards printed by the University of Oxford. Dr. 

 Maskelyne, on the contrary, obtained leave from the British Govern- 

 ment to have his observations printed at the public expense under 

 the direction of the Royal Society, who are the legal visitors of the 

 observatory, appointed by the royal sign manual; and by thus 

 causing the observations of the Astronomer Royal to IK- recorded 

 publicly, he supplied a great want which had hitherto existed both 

 in the English and French establishments. He also made several 

 improvements in the arrangement and employment of the instru- 

 ments used in the observatory, particularly, by enlarging tlie slits 

 through which the light was admitted; by making the, eyeglass of 

 his transit telescope moveable to the place of each of the wires of 

 the micrometer ; and above all, by marking the time to tenths of a 

 second, a refinement which had never been attempted before. 



* 20,0002., the reward offered for a chronometer sufficiently exact to correct 

 the longitude within certain limits required by Act of Parliament. 



