THE SUN'S MOTION IN SPACE. 155 



sphere are of course considered as the points to and from which 

 the sun is moving. 



(14) Du Sejour, 1786. — It is stated in the Connaissance des 

 Temps for 1809, 1 that Dusejour occupied himself with the problem 

 of solar motion. This would probably be found in his analytical 

 treatise of the movements of celestial bodies. 2 



(15) Klilgel, 1789. — The Berlin ephemeris in 1789 contained 



formulas by Kliigel, 3 for deducing the direction of the sun's path 



in space, the point which he assigned having for its coordinates 



the values 



R.A. = 260°, D.= +27° 



The deduction was also based on the proper motions of Mayer's 



table. 



(16) Wurm, 1795. — The Berlin Astronomical Yearbook was in 

 1795 again the repository of a discussion of the trend of our 

 system in the stellar universe ; viz., in Wurm's article on the 

 degree of certainty of our knowledge of the movement of our 

 system through space. 4 



(17) Prevost P. and Maurice, F., 1801. — In the memoirs of the 

 Berlin Academy in 1801, a determination by Prevost and Maurice, 5 

 based on a discussion of the proper motion from 1756 to 1797 of 

 39 stars, of the point to which the motion of our system is directed, 

 was given. The result was also published afterwards in the 

 Berlin Ephemeris, viz., in 1805. 6 



(18) Biot, 1805. — Jean Baptiste Biot in his Traite elementaire 

 d'astronomie physique, 7 published in 1805, also deduced formulae 



1 Sur le mouvement du systeme planetaire, pp. 377-382. 



2 Traite analytique des mouvemens apparens des corps celestes, Paris 

 1786-9, 2 tomes 4°. 



3 Trigonometrische Formeln zu der Untersuchung uber die Fortriick- 

 ung der Sonne und der Sterne. — Berl. Astr. Jahrb. 1789, 214. 



4 Ueber den Grad der Zuverlassigkeit unserer Kenntniss von einer 

 eigenen Bewegung unserer Sonnensystems. — Berl. Astr. Jahr 1*795, p. 175. 



5 Mem. Berlin Acad. 1801, pp. 118 - 131. 



6 Bode, Berl. Astr. Jahrb,, 1805, pp. 113-126. 



7 The edition to which I have access is 1811. The treatment of the 

 problem is entitled " Sur le mouvement de translation du systeme 

 planetaire/' t. in., additions pp. 114- 129. 



