Gravitational Matter through Infinite Space. 



177 



§ 21. I need scarcely repeat that our assumption of equable 

 distribution is perfectly arbitrary. How far from being like 

 the truth is illustrated by HerscheFs view of the form of the 

 universe as shown in Newcomb's Popular Astronomy, p. 46K 

 It is quite certain that the real visible stars within the 

 distance r (5) from us are very much more crowded in some 

 parts of the whole sphere than in others. It is also cert un 

 that instead of being all equally luminous as we have taken 

 them, they differ largely in this respect from one another. 

 It is also certain that the masses of some are much greater 

 than the masses of others ; as will be seen from the following 

 table, which has been compiled for me by Professor Becker 

 from Andre's Traite cV Astronomie SteUaire, showing the 

 sums of the masses of the components of some double stars, 

 and the data from which these have been determined. 



\ Ma j oi" axis 



ParalU 



in 

 seconds. 



in terms of 

 semi-major 



axis of 

 earths orbit. 



a Centaur i .. 

 61 Ovgui 



Sirius 



Procyon ... 

 o 2 Eridani .. 

 r) Cassiopeia} 

 p Ophiuchi ... 



y Virginis 

 y Leonis .. 



075 



18-17 



0-44 

 039 



2948 



8-31 



027 



5-84 



019 



572 



015 



8-20 



015 



400 



005* 



399 



002* 



1-98 



'Jo 



GS 



24 



4 



28 

 39 

 30 



79 t 

 102 t 



Period 

 in 



years. 



84 

 783 



52 



40 

 176 

 190 



83 



M+M' 



in units 



of the 



sun's mass. 



20 

 05 

 3-2 



(i-3 

 09 

 43 

 36 



194 

 407 



1.V0 

 65 



§ 22. There may also be a large amount of matter in many 

 stars outside the sphere of 3.10 16 kilometres radius, but however 

 much matter there may be outside it, it seems to be made 

 highly probable, by §§ 11-21, that the total quantity of matter 

 within it is greater than 100 million times, and less than 2000 

 million times, the sun's mass. 



I wish, in conclusion, to express my thanks to Sir Norman 

 Lockyer, to the Astronomer Royal Mr. Christie, to Sir 

 Robert Ball, and to Prof. Becker, for their kindness in taking 

 much trouble to give me information in respect to astronomical 

 data, which has proved most useful to me in §§ 11-21 above. 



* Parallax calculated from dynamical determinations of ratio of 

 semi-major axis of double star's orbit to semi-major axis of earth's orbit. 



+ From spectroscopic observations by Belopolsky of Poulcowa, com- 

 bined with elements of orbit. 



JPhiL Mag. S. 6. Vol. 2. No. 8. Aug. 1<J01. X 



