126 Sherman—Study upon the Atmosphere of B Lyre. 
Art. XIV.—A short Study upon the Atmosphere of B Lyre ; 
by Orray T. SHERMAN. 
A COMPARISON of the observations upon the spectra of those 
stars admitted to possess a spectrum comprising bright lines 
leads to the conclusion that, while persistent in place, the 
bright line is not persistent in intensity. That this is the case 
in the solar chromosphere, # Lyre, 7 Cassiopeiz, R.Geminorum, 
y and 7 Argus, the Wolf and Rayet stars, and through the 
courtesy of Dr. Konkoly we add y Ceti, may not be doubted. 
In the others also it seems probable. This peculiarity, now 
presented as a characteristic of the bright line in stellar spectra, 
affords a distinction between bright line light, bright back- 
ground space, and any accidental disturbance the spectrum 
light may suffer. 
Under its guidance the observation was extended to noting 
the relative places of every persistent or at times outflashing 
break in the spectrum light, and the single observation was re- 
placed by a series as frequently as opportunity allowed. For 
greater intensity of bright line light, the sharply focussed star 
was made to replace the slit, the jaws being symmetrically 
opened, so that, while allowing the full disc. to pass, any dis- 
placement soon caused a diminution of the stellar hight. For 
reference spectra the jaws were reclosed. The cylindrical lens 
was removed. ‘The observing telescope was of low power. Tor 
least intensity of background light, the highest dispersions 
practicable were employed. No foreign light was permitted, 
the telescope being set during the day so as to be swept upon 
the star. The record was automatically made. The routine of 
observation is as follows: For some time previous the ob- 
server's eye is kept in the dark. Seated at his telescope, he 
has then before him a faint, barely traceable line of light, bead- 
ing or imbedded in which are a number of bright monochro- 
matic stellar images. These points are brought so as to be 
bisected by the edge of the thick cross-bar which it is desirable 
to employ. The position is recorded and the observer proceeds 
to the next dot. In this way he has usually passed through 
the first, second and a portion of the third spectrum. At the 
end of the observation the position of the bright lines afforded 
by a salted alcohol flame or Pliicker’s tube are added. The 
shp is withdrawn. The relative position of the punctures are 
measured and the wave-length reduced by a proper formula. 
The record of the three spectra combined in one is then re- 
corded as the result of the day’s observation. ‘he spectra in 
which the especial line has been observed forms a measure of 
its intensity. In combining one day’s work with the others, 
those lines which lay nearest together have been referred to 
