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IV. Comparative Photographic Spectra of Stars to the 3 Magnitude. 

 By FRANK MC(/LEAN, F.R.S. 



Received March 24, Read April 8, 1897. 



[PLATES 1-17.] 



THE 160 photographs which accompany the paper include, with insignificant excep- 

 tions, all stars equal to and brighter than the 3^ magnitude, contained in five out of 

 eight equal areas, into which the celestial sphere has been divided. 

 The diagram shows the position of the eight areas consisting of 



Two upper galactic polar regions, viz., A and A A. 



zones B BB. 



Two lower galactic zones ,, G CC. 



,. polar regions ,, D ,, DD. 



The galactic zones extend to 30 from the galactic plane. 



The object of the division into equal areas is to bring out roughly any differences 

 of distribution of the different types of spectra in relation to the galactic plane. 



25.5.98 



