with an Account nf a JVork of Professor Vessel. G 1 



part of Drad!ey's were made. Bessel finds the latitude of the 

 <juadrant, from 2000 observations of Bradley, exactly a second 

 greater than Pond makes tliat of his circle ; and it is natural to 

 inquire vvhellier a part of the difference may not depend on the 

 different situation of the instruments. 



Bremci), Ijt.'i Jmif. 1810. WiLI.IAM OlbERS. 



Professor Bessel's work will be entitled Fi/ndamenta Astro- 

 vnviice pro Anno 1755, deduct a ex Obsorvationilus Viri incom- 

 paral;lis J. Bradley. It is the result of the labour of seven 

 whole years, and contains a number of determinations of the ut- 

 most importance to astronomy. The eNtreme accuracy of Brad- 

 ley's melhods of observing;, combined with the exceliesice of his 

 instruments, made it possible for him to attain a degree of pre- 

 eisicn, which is of so much tlie more value, ai half a century is 

 now claj)sed since the period to which they relate. All the ele- 

 ments uhich have any influence on astronomical observations are 

 here deduced from Bradley's observations alone. 



The sections of the work are these : I. Examination of the 

 instruments, and of their corrections. II. 01)seivations of the 

 equinox. III. Latitude of Greenwich. IV. Refraction. V. Ap- 

 plication of the latitude and refraction to the observations of the 

 «olstice and the equinox. VI. Examination of the old mural 

 quadrant : law of its variation : new examination of right as- 

 censions. VII. Gcricral and special tables of aberration and 

 nutation. ^'11 1, llegister of the clock from 1750 to 1702. 

 IX. Annua! parallax of some of the fiTied stars : constant multi- 

 plier for aberration. X. Catalogue of all the stars observed by 

 Bradley; 31(jG which are found in later catalogues, and 108 

 observed but once, and not elsewhere noticed; some of which 

 may possibly have been planets, but the Georgian planet occurs 

 but once among them. XI. Prficession of the equinoxes. XII. 

 Proper motion of the fixed stars. XIII. Comparison of the re- 

 sults with otiitr observations. 



The work is written in Latin, and will contain about 400 

 pages in folio : the price to subscribers will be ten dollars, con- 

 ventional currency, to be paid on delivery. The only reason for 

 •oliciting a subscription is to contribute to the advancement of 

 science. The author would readily have renounced ail hopes of 

 remuneration for his labours ; but so little encouragement is 

 given in Germany to works of the kind, that no bookseller 

 could be found to undertake the expenses of the publication. A 

 hundred subscribers will be sufficient to cnai)!e the author to 

 jMCtt these expenses ; and their names will be published as be- 

 urfactors to the science of astronomy. 



•#* The Editor of the Philosophical Magazhie has been re- 



<iue3ied 



