The first-known examples of the class of gaseous stars--Beta Lyrae
and Gamma Cassiopeiae--were noticed by Father Secchi at the outset
of his spectroscopic inquiries. Both show _bright_ lines of hydrogen and
helium, so that the peculiarity of their condition probably consists in
the intense ignition of their chromospheric surroundings. Their entire
radiating surfaces might be described as _faculous_. That is to say,
brilliant formations, such as have been photographed by Professor Hale
on the sun's disc,[1387] cover, perhaps, the whole, instead of being
limited to a small portion of the photospheric area. But this state of
things is more or less inconstant. Some at least of the bright rays
indicative of it are subject to temporary extinctions. Already in
1871-72, Dr. Vogel[1388] suspected the prevalence of such vicissitudes;
and their reality was ascertained by M. Eugen von Gothard. After the
completion of his new astrophysical observatory at Hereny in the autumn
of 1881, he repeatedly observed the spectra of both stars without
perceiving a trace of bright lines; and was thus taken quite by surprise
when he caught a twinkling of the crimson C in Gamma Cassiopeiae,
August 13, 1883.[1389] A few days later, the whole range including D_3
was lustrous. Duly apprised of the recurrence of a phenomenon he had
himself vainly looked for during some years, M. von Konkoly took the
opportunity of the great Vienna refractor being placed at his disposal
to examine with it the relighted spectrum on August 27.[1390] In its
wealth of light C was dazzling; D_3 and the green and blue hydrogen rays
shone somewhat less vividly; D and the group _b_ showed faintly dark;
while three broad absorption-bands, sharply terminated towards the red,
diffuse towards the violet, shaded the spectrum near its opposite
extremities.

The previous absence of bright lines from the spectrum of this star was,
however, by no means so protracted or complete as M. von Gothard
supposed. At Dunecht, C was "superbly visible" December 20, 1879[1391];
F was seen bright on October 28 of the same year, and frequently at
Greenwich in 1880-81. The curious fact has, moreover, been adverted to
by Dr. Copeland, that C _is much more variable than F_. To Vogel, June
18, 1872, the first was invisible, while the second was bright; at
Dunecht, January 11, 1887, the conditions were so far inverted that C
was resplendent, F comparatively dim.

No spectral fluctuations were detecte