The GEORGIUM SID US. 309 



OF all the theories of this Planet which I have feen, that of 

 M. DE LA PLACE, communicated to the Royal Academy of 

 Sciences at Paris, appears the moft accurate, and very nearly 

 correfponds to the obfervations which have been made fince 

 the time of its publication. This theory was announced to the 

 public in the Connoiffance des Mouvemens Celeftes, as deduced di- 

 reclly from the recent obfervations, by a method peculiar to 

 M. DE LA PLACE. This I hoped to find in an excellent differ- 

 tation on the elliptical motion of the Planets, published by him 

 in 1784. But, although I found this work full of new and va- 

 luable information, as might be expected from this eminent 

 mathematician, I was difappointed in my hopes of learning 

 the procefs by which he had deduced his theory of the new 

 Planet. He has, indeed, infer ted in this work the elements of 

 its orbit, and the four obfervations which he had employed for 

 determining them, by a new method of confidering the plane- 

 tary motions, with which he was then occupied, but which he 

 does not explain. When I compared M. DE LA PLACE'S theo- 

 ry with thofe obfervations, I found fuch differences as would 

 have allowed him to make choice of elements confiderably dif- 

 ferent. It appears, therefore, that, before applying his method, 

 he has corrected the obfervations on fome juftifiable principle, 

 which I regret exceedingly that he has not communicated, fince 

 he has been fo fuccefsful in the ufe of it. It would, doubtlefs, 

 have been much more deferving of the notice of mathema- 

 ticians than the empirical one which I have adopted in the fub- 

 fequent part of this paper. 



IN fpring 1784, I framed a fet of elements which corre- 

 fponded with the obfervations made at that time with abundant 

 accuracy. Mr MINTO, whom I have already mentioned, alfa 

 communicated to me elements, little differing from mine, and 

 equally accurate. Both thefe were deduced from a fuppofition 

 that the Star obferved by MAYER was the new Planet. We had, 

 by this time, great advantages over our predeceflbrs j for a 



much. 



