356 
ASTRONOMY: W. S. ADAMS 
A similar comparison with the lines measured in the spectrum of Nova 
Geminorum of 1912 1 shows clearly the presence of many of these lines in the 
latter star as well. The displacement, however, is only about one-half as 
great as in the case of Nova Aquilae. To illustrate the character of the lines 
identified and the displacements involved the results for a portion of the 
spectrum between X 4500 and X 4600 are given in table L 
The lines in the spectrum of Nova Geminorum are much more hazy and ill- 
defined than those in Nova Aquilae and the agreement is much less satisfac- 
tory. This is due in part to the fact that the earliest photographs of the 
spectrum of Nova Geminorum were obtained at a longer interval after the 
discovery of the star than in the case of Nova Aquilae, and that during this 
interval the absorption lines had begun to grow faint and disappear. About 
forty lines common to the spectra of these two stars have been identified in 
the region between H5 and H/3. 
TABLE 1 
WAVE-LENGTH 
DISPLACEMENT 
ELEMENT 
Sun 
Nova Aquilae 
(June 12) 
Nova 
Geminorum 
Nova Aquilae 
A 
Nova 
Geminorum 
A 
4501.4 
4478.2 
4489.3 
-23.2 
-12.1 
Enhanced Ti 
4508 . 5 
4485.3 
4495 . 5 
23.2 
13.0 
Enhanced Fe 
4515.5 
4492.0 
4505.2 
23.5 
10.3 
Enhanced Fe 
4520.4 
4497.1 
4508.1 
23.3 
12.3 
Enhanced Fe 
4522.8 
4499.2 
4511.9 
23.6 
10.9 
Enhanced Fe 
4528.8 
' 4505.3 
4518.4 
23.3 
10.4 
Arc line Fe 
4534.1 
4510.5 
4522.8 
23.6 
11.3 
Enhanced Ti 
4549.8 
4526.1 
4537.6 
23.7 
12.2 
Enhanced Fe, Ti 
4556.1 , 
4531.7 
4543.8 
2-4.4 
12.3 
Enhanced Fe 
4558.8 
4535.0 
4547.0 
23.8 
11.8 
Enhanced Cr 
4563.9 
4540.1 
4551.6 
-23.8 
-12.3 
Enhanced Ti 
It is known from the investigations of Campbell and Wright on the spectrum 
of Nova Persei of 1901 2 that the displacements of the absorption lines of hy- 
drogen were directly proportional to wave-length in this star, and the same 
result was found for Nova Geminorum by other observers. The identification 
of the metallic lines in the case of Nova Aquilae and Nova Geminorum makes 
a study of their displacements of especial interest in this regard. For this 
purpose the average displacement and the average wave-length have been 
formed for groups of lines distributed throughout the spectrum. In the less 
refrangible region longer intervals have been included because of the smaller 
number of lines available and the larger range of error in wave-length. The 
results are given in table 2. 
The values for Nova Persei are by Campbell and Wright 2 and those for Nova 
Aurigae of 1892 are by Campbell and Vogel. 3 
