THE SUN'S MOTION IN SPACE. 213 



Kobold, furnishes an example with 43 stars of class II. 1 These 

 gave by direct solution the result 



R.A. = 264°-3, D. = - 3°-5 

 Starting with R. A. = 270° D. = + 30° as assumed values, the first 

 approximation led to 



R.A. = 267-°1, D. + ll-°2 

 Again proceeding with R. A. = 270° and D. = + 1 1 *°2 as the assumed 

 values, the result for second approximation was 



R.A. = 267°1, D.= +2°7 

 from which Kobold concluded that doubtless the differential formula 

 leads finally to the same point as is obtained by the direct solution. 

 Whatever the explanation of the peculiar result obtained by 

 Yowell, the one which he offers is certainly not correct. 



Additional Memoirs, etc. 

 The following memoirs and results were overlooked when com- 

 piling, in proper historical sequence, the work of the various 

 investigators. They have advisedly been numbered so as to fall 

 in their proper place according to the general plan. It has not, 

 however, been possible to interpolate them. In the tabulated 

 results hereinafter given, each appears in its proper place. 



(4a) Jacques Cassini, 1738. — On the 12th November, 1738, 

 J. Cassini submitted a memoir to the French Academy of Sciences, 

 on the variations observed in the situation and motion of several 

 fixed stars, 2 including those mentioned by Halley. 



(10a) Bailly, J. S., 1775. — In his history of modern astronomy 

 Bailly, like Michell, also considered the question of the possibility 

 of solar motion. 3 



(64a) Gylde'n, 1871.— In Oct. 1871, Gylden determined the 

 right ascension of the direction of solar motion from four groups 



1 Bemerkungen zu dem Artikel : Note on a new method of determining 

 the solar apex, by B. I. Yowell, in Astr. Journ. Nr. 479. Astr. Nach., 

 Bd. clii., pp. 279 - 280. 



2 Histoire de l'Acad. roy. des Sciences, Paris 1738, p. 331. 



3 Histoire de FAstronomie moderne, Paris 1775 - 1783, t. n., p. 662 et seq. 



