THE SUN'S MOTION IN SPACE. 185 



underlying assumptions, a point discussed by him at some length, 

 Monck abandoned entirely all classification in respect of magni- 

 tude, and all assumptions with regard to distance. 1 Employing 

 Dunkin's (i.e., Main's) 1,167 stars, he tabulated the numbers in 

 each hour of R.A. shewing increasing, and also those shewing 

 diminishing N.P.D. The great preponderance of stars with 

 increasing north polar distances, indicated that the apex of solar- 

 motion was in the northern hemisphere, and that the north declin- 

 ation was considerable. The apex seemed to lie between R.A. = 

 16 hrs. and R.A. = 21 hrs., and the declination to be about -f- 45T 

 A second table was then formed, giving similarly the numbers of 

 stars with increasing and also with diminishing right ascensions. 

 This table shewed the R.A. of the apex to lie between 18 hrs. and 

 19 hrs. Monck concluded further that this method would also 

 serve to shew the rate of our progression, provided we assume 

 that the stars are moving indifferently in every direction. He 

 roughly estimated the velocity to be twenty miles per second, 

 subject to an uncertainty of several miles. His rough values are 

 R.A. = 280°, D. = + 45°, V. = 20 miles per second. 

 Monck thinks that the proper motions of not less than 10,000 

 stars are requisite for determining the apex 'within 2 or 3 degrees,' 

 or the sun's velocity 'without a considerable percentage of error.' 

 The paper contains no rigorous mathematical statement of the 

 fundamental assumptions, and the attempt at a quantitative 

 estimate is admittedly 'rough' only. 



(91) Seeliger, 1892, (March). — Seeliger in his public address at 

 the Munich Academy of Sciences, on the occasion of the 133rd 

 anniversary of its foundation, 2 makes some important observations 

 as to correct conceptions of the problem of solar motion, pointing 

 out that it is 'very frequently, perhaps most frequently miscon- 

 ceived,' 3 as was established by L. Lange. 4 



1 1. The Sun's Motion in Space, I. and II. — Publications of the Astr. 

 Soc. of the Pacific, Vol. xiv., No. 22, pp. 70 - 77, 1892. 



2 Ueber allgemeine Probleme der Mechanik des Himmels, pp. 1 - 29, 

 Mxinchen, 1892. ' 6 Loc. cit., p. 29. 



4 Die geschichtliche Entwickelung des Bewegungsbegriffes, etc., 

 Leipzig, 1886. 



