434 



distinguished of their number should be necessarily so slight and im- 

 perfect, 



Mr. Pond succeeded Dr. Maskelyne as Astronomer Royal in 1810, 

 and retired from that important situation,, under the pressure of many 

 infirmities, in the autumn of last year : he was formerly a member of 

 Trinity College, Cambridge, where he was a pupil of Professor Lax, 

 whose name appears also in the list of deaths which has been just 

 read to you. After leaving the University, he travelled in many 

 parts of the East, and particularly in Egypt, partly urged by the 

 spirit of adventure which is natural to youth and partly with a view 

 of making astronomical observations in climates more pure and more 

 regular than our own. After his return home in 1800, he settled at 

 Westbury, in Somersetshire, and devoted himself, amidst other pur- 

 suits, chiefly to astronomy, making use of a circular instrument of c l\ 

 feet diameter, which had been constructed and divided by Troughton 

 with more than ordinary care. With this instrument he observed 

 by a peculiar method, the declinations of some of the principal fixed 

 stars, which were communicated to the Royal Society in 1806 ; and 

 it afterwards enabled him to establish the fact of a change of form 

 in the great quadrants at Greenwich, a discovery of great importance, 

 inasmuch as it not only led to the substitution of circular instru- 

 ments for them in our national observatory, but subsequently like- 

 wise to his own appointment as Astronomer Royal. 



After Mr. Pond's establishment at Greenwich, he communicated 

 to the Royal Society from time to time, not merely the general re- 

 sults of his labours, but likewise his views of the theory of astrono- 

 mical observations and of the grounds of judging of their relative 

 accuracy : his system was to observe differences of declination and 

 right ascension, making every star a point of departure for the rest, 

 and considering the pole as a point in the heavens whose position 

 was capable of a determination, equally, and not more accurate than 

 that of any given star. To such a view of the theory of observation, 

 circular instruments were particularly adapted, and there is no reason 

 to doubt that the relative catalogues of the stars which were formed 

 by Mr. Pond were more accurate and complete than those of any 

 preceding or cotemporary observer. Such a result, however, might 

 have been reasonably expected from the great powers and resources 

 of the establishment over which he presided and which he had him- 

 self been the chief means of calling into action. 



The method which was adopted by Mr. Pond to determine the 

 limits of the annual parallax of certain fixed stars by means of fixed 

 telescopes of great focal length, was singularly ingenious and com- 

 plete. The existence and amount of such a parallax had been asserted 

 and assigned by Dr. Brinkley, in a Lyrae, a Aquilae, and a Cygni ; 

 but this opinion, although most ingeniously and even obstinately vin- 

 dicated and maintained by him, was, in the judgement of most other 

 astronomers, most decisively negatived by Mr. Pond, who showed 

 that the parallax of those fixed stars, supposing its amount to be 

 sensible, was confined within the limits of the errors of the most deli- 

 cate and perfect observations which have been hitherto made. There 



