36 



HISTORY OF ASTRONOMICAL DISCOVERY. 



should not want such assistance, immediately instituted the office of astronomer royal, 

 and determined upon founding an observatory. The site selected by Wren was 

 a commanding eminence in Greenwich Park, in former times the seat of Duke Hum- 

 phrey's tower, within view of all vessels passing along the Thames ; a spot which Piazzi was 

 accustomed to call the "paradise" for an observer; being free from a fluctuating atmo- 

 spheric refraction which annoyed him in the climate of Sicily. The foundation-stone was 

 laid August 10th, 1675. An original inscription, still existing, states the design of v the 

 building the benefit of astronomy and navigation. The observatory has been succes- 

 sively under the superintendence of Flamstead, Halley, Bradley, Bliss, Maskelyne, Pond, 

 and Airy, its present head, with assistants for its proper management. It is not a spot 

 devoted to star-gazing, and the general observance of celestial phenomena, but essentially a 

 place of business, carrying on by day and by night, when the weather permits, those ob- 

 servations of the sun, moon, planets, and principal stars, passing the meridian, from which 

 the nautical almanac derives its information. This has been done with admirable regularity 

 for a long series of years, nor has Europe any data comparable with the Greenwich tables. 

 During the interval in which the office of astronomer royal is necessarily vacant, the 



business of the observatory proceeds; and 

 that interval is now less than formerly. 

 Thirty-three days elapsed between 

 Bradley's last observation and Bliss's 

 first; fifty-three between Bliss's last and 

 Maskelyne's first; four between Mas- 

 kelyne's last and Pond's first ; and two 

 between Pond's last and Airy's first. It 

 has been asserted by Baron Zach, that, 

 if the other observatories had never ex- 

 isted, our astronomical tables would be 

 equally perfect; and Delambre, when 

 delivering an eloye on Maskelyne be- 

 fore the Institute of France, remarked, 

 that if by some grand revolution in the 

 moral or physical world, the whole of 

 the monuments of existing science should 

 be swept away, leaving only the Green- 

 wich observations and some methods of 

 computation, it would be possible to re- 

 construct from these materials the entire 

 edifice of modern astronomy. 



A few years ago it was resolved by 

 the Lords of the Admiralty, that the 

 time should be shown at Greenwich once 

 in every day of the year. This is done 

 by means of a large black ball which surmounts the north-western turret of the ob- 

 servatory. The ball, seen down in the vignette, is elevated by machinery to the index, 

 showing the four cardinal points ; and, the instant it begins to descend, marks the mean 

 solar time to be 1 P.M. Being plainly observable from the Thames, the arrangement 

 affords a convenient opportunity for seamen to regulate their chronometers and clocks. 



The fame of FLAMSTEAD, the first astronomer royal, does not rest upon any brilliant 

 discovery, but upon an enlightened view of the importance of accurate observation, and 

 the unwearied zeal and industry with which he pursued it. A better representation of 



