1888.] of the various Species of Heavenly Bodies. 85 



which, however, are many stars between the ninth and tenth, is 

 324,118. The most complete catalogue of variables (without distinc- 

 tion) that we have has been compiled by Mr. Gore, and published in 

 the 'Proceedings of the Royal Irish Academy' (series ii, vol. 4, 

 No. 2, July, 1884, pp. 150—163). I find 191 known variables are 

 given; of these 111 are in the northern hemisphere and 80 in the 

 southern hemisphere. 



In the catalogue of suspected variable stars given in No. 3 of the 

 same volume (January, 1885, pp. 271 — 310), I find 736 stars, of 

 which 381 are in the northern and 355 in the southern hemisphere. 



Taking, then, those in the northern hemisphere, both known and 

 suspected, we have the number 492.. 



We have then as a rough estimate for the northern heavens one 

 variable to 659 stars taken generally. 



The number of objects of Group II observed by Duner, and 

 recorded in his admirable memoir, is 297; of these forty-four are 

 variable. 



So that here we pass from 1 in 657 to 1 in 7. 



Of the great development of variability-conditions: in this group 

 then there can be no question. 



To apply the other tests above referred to, I have made a special 

 study of the observations of each variable recorded by Duner. I find 

 they may be grouped in the following 



Table of Variables. . 

 1. All bands visible but narrow. 



No. in 

 Uuner 

 Cat. 



Name. 



Max. 



Min. 



Period. 





269 





4 ? 



5 ? 



irreg. 





2. Bands well marked, but feebler in Red. 



No. in 

 Duner 

 Cat. 



Name. 



Max. 



Min. 



Period. 





186 

 222 

 81 



W Herculis (? V) . . 

 S Hydra 



>8 

 7 

 7-8 



<12 

 12 

 <12 



290? 



270 



256 





