G92 
PROFESSOR J. N. LOCKYER ON THE PHOTOGRAPHIC 
(1.) Sub-division a. 
Characteristics of the Spectra. 
Ill all the stars in question the hydrogen lines are well marked, though not of such 
extreme breadth as in stars like Sirius. The total number of lines in the spectra is 
remarkably small, as compared with the number seen in stars which resemble the Sun. 
The lines seen in addition to those of hydrogen vary very considerably in passing 
from star to star, though some lines are common to them all. It will, therefore, be 
convenient to further sub-divide the stars, according to the presence or absence of 
individual lines. Such a classification is given in the following Table. 
Stars in which there occur strong lines at 4025, 4120‘5,4143, 4388, 4471, in addition 
to hydrogen lines of moderate breadth. 
11) 
(2) 
(3) 
(4) 
(5) 
(6) 
There are strong 
lines at 4481, 
4233, 4127, and 
4130. The lines at 
4025 and 4471 are 
very feeble. A 
few lines of iron 
are added. 
The line.s at 4025 
and 4471 ai’e 
much intensified, 
the last as strong 
as 4481. There 
are no lines of 
iron. 
The lines at 4481, 
4127, 4130, are 
now faint, while 
4025 and 4471 are 
very strong. 
The lines at 
4025 and 
4471 are still 
very strong, 
and lines at 
4414'5 and 
4088 are 
seen. 
The line at 
4414'5 is in¬ 
tensified, 
while that at 
4088 is 
feebler. 
Stars which 
show no lines of 
impoi'tance 
except the five 
typical lines. 
a Cygni 
/3 Orionis 
/I Tanri 
07 Ophinchi 
e Cygni 
7 Orionis 
/I Cam's Alajoris 
e Orionis 
( Orionis 
G Orionis 
If Orionis 
k- Orionis 
e Persei 
a. Virginis 
7 Pegasi 
f Persei 
\ Orionis 
f Tanri 
>] Urste IMajoris 
Scorpii 
0 Scorpii 
/I Scorpii 
<r Scorpii 
T Scorpii 
f Ophinchi 
O' Sagittarii 
The preceding Table only refers to the more important lines in the spectra, and in 
order to facilitate comparisons, the following more complete one has been compiled. 
The wave-lengths were determined in the first instance from photographs taken with 
the two 10-inch prisms (Instrument C), and have since been confirmed by photographs 
taken with the larger dispersion of the 6-inch Henry prism of 45° (Instrument B). 
The values are believed to be accurate to four figures, and in cases where decimals are 
added, greater accuracy was attainable. The numbers following the wave-lengths 
indicate as nearly as possible the intensities of the lines, 6 being the strongest, and 
1 the feeblest. 
[Note, Aug. 15, 1893.—The wave-lengths have been determined by reference to 
the lines of hydrogen (marked H, h, and G in the plates), which appear in the spectra 
of all the stars which have been photographed.] 
