718 
PROFESSOR J. N. LOCKYER ON THE PHOTOGRAPHIC 
was then intermediate between a Orionis and a Tauri, and that it should, therefore, 
he placed in Species 15. It is, perhaps, possible that the spectrum is slightly 
varialjle. 
Other eye observations at Kensington,showed that a Ceti should be transfeired 
to Species 15. Including /3 Andromedce and this star we should, therefore, have the 
following relation :— 
Order from eye observations. 
Andromedse. 
a Ceti. 
r a Orionis. 
L V Bootis. 
Order from photographs. 
^ Andromedas. 
a Ceti. 
V Bootis. 
a Orionis. 
( 
a Herculis. 
8 Virginis. 
-< 
a Scorpii. 
/3 Pegasi. 
8 Ophiuchi. 
Geminorum. 
Persei. 
r 
a Scorpii. 
^ Pegasi. 
p Persei. 
a Herculis. 
Virginis. 
Ophiuchi. 
Geminorum. 
It will be seen that very nearly the same order as that derived from eye observa¬ 
tions is arrived at from the photographs, and the wonderful thing is that the 
olrservations of Duner will bear the severe test which has thus been applied to them. 
(Stage 2.)—At this stage we should expect— 
(a.) Diminution in the amount of continuous absorption. 
(6.) Spectrum consisting of dark metallic lines, but possibly differing from the 
solar s})ectrum. 
These conditions are fulfilled by the stars of Table C, Sub-division /8, and Table B, 
Sub-division a, of which a Tauri and y Cygni may be taken as types. The continuous 
absorption is least in latter. These spectra show numerous metallic lines, but they 
do not exactly resemble the solar spectrum. The h 3 nlrogen lines are comparatively 
thin, while other lines have very different intensities as compared with lines in the 
solar spectrum. 
In these stars we liave to deal with the varying volatilities of the meteoritic 
constituents of the swarm, while in the case of stars which are cooling we have to 
* ‘ Roy. Soc. Proc.,’ vol. 45, p. 385. 
