722 
PROFESSOR J. N. LOCKYER ON THE PHOTOGRAPHIC 
The stars .witli flutings in their spectra are probably among the coolest^ as we know 
from laboratory experiments that flutings are alwmys associated with low temperatures. 
Assuming these distinctions to be true, it is seen that when the two series of ascending 
and descending spectra are united in this wmy, the hottest stars, as we should expect, 
fall in the middle of the combined series. 
(3.) Kelation of the Groups to the Tabular Di^hsioxs. 
We may next proceed to inquire into the relationships of the groups in the classifi' 
cation first suggested by the eye observations to the various sub-divisions in the 
tables of photographs which have already been given. 
The Ascending Series. 
It has already been shown (p. 707) that the most probable sequence of spectra in 
what we have now demonstrated to be the ascending series is as follows, the stars of 
highest temperatures being placed at the head of the list. 
Table A, Sub-division y, 1. 
,, ,, ct, 5. 
,, ,, a, 4. 
,, ,, a, 3. 
j) 2. 
,, „ b 
,, B, ,, a. 
„ 0, „ /3. 
If, as in the original classification, we take Group II. to include all the stai’s with 
dark flutings. Group III. to include all the stars of increasing temperature which have 
iinu spectra, and Group IV. to include the hottest stars, we shall evidently have the 
following relation :■— 
