THE SOLAR ECLIPSE. 255 
total eclipse of 1860, namely, the shortening of duration of totality, the visibility 
of the moon’s limb before and after totality, &c., may be explained. 
Mr. d’Abbadie (57) observed position-angles and altitudes of the protuber- 
ances @ and e, and, in fact, the latter was observed before the appearance of the 
sun with the position-angle of 260°, and after the appearance of the sun, as a 
new protuberance, with the angle of 263°. The conclusions to which his ob- 
servations lead have been already mentioned above. His polarization observa- 
tions agree, indeed, with those of Mr. Prazmowski, but cannot be considered as 
decisive. 
The account of Mr. Gilliss (73) is very remarkable, and we can only wish 
that the things noted could have been exhibited in more detail and explained 
by drawings. The station was'in a prairie (Muck Prairie) near Steilacoom, in ‘ 
a bleak and little cultivated part of Washington Territory, and the dampness 
was so great that the object-glass of the telescope required to be wiped off from 
time to time, as a deposition was constantly forming. If we assume that in the 
photographed drawings, accompanying the memoir, north and south only are 
inverted, and not east and west, so that south is above, north below, west on the 
right, and east on the left, then Mr. Gilliss observed protuberance g with the 
position-angle of 255° to 258°, and this came out first, and with striking bright- 
ness as a cloud-pyramid of 2’ base and 1’ altitude. As the moon advanced the 
base increased, while the altitude remained the same; notwithstanding, the ap- 
pearance made an impression upon Mr. Gilliss as though the protuberance came. 
gradually more into view behind the advancing moon. A smaller protuberance 
(doubtless f) appeared simultaneously under the angle of'268° to 273°, and 
towards the end of totality the protuberance 4 (?) was also perceived. ‘These 
are the only objects which Mr. Gilliss speczal/y mentions. He remarks, how- 
ever, that the number of the protuberances was considerable, and that they 
commenced to appear about 30* after the beginning of totality, after a small 
white line had been seen immediately around the moon’s limb, and outside of 
this line a crown of red points or pearls which seemed to run around the moon. 
But the most striking thing in the appearance were rainbow-like and rainbow- 
colored small bands of equal radius with the moon, which, in great number, 
following each other upon the dark lunar disk, moved inward toward the centre 
from east and west. Mr. Gilliss leaves it undecided whether a real appearance 
was seen here, or only an optical phenomenon arising from physiological causes, 
yet he adds a short description by Mr, Goldsborough, at Steilacoom, from which 
he thinks it may be concluded that the latter saw the same phenomenon. At 
the beginning of the totality the moon showed itself spherical, as though seen in 
a stereoscope. 
Mr. Burat (25) designates the outer limit of the corona as elliptical in such a 
way that the breadth at the solar equator was greater, and less at the poles. 
Among the protuberances he noticed 4, ¢, d, e, but no accurate comparison can 
be instituted, as he has not given the times. 
Mahmoud Bey (70) observed the eclipse in Dongola, on the Nile, and saw at 
first 6, but near the end of totality 7 protuberances, among which were 8, 
(observed position-angle 109° to 121°,) f, (observed angle 278°,) and c, which 
last appeared as consisting of two isolated clouds. 
In the memoir of Mr. Midler (34) it is especially worth while to notice the 
indication of a circumstance, not previously brought into consideration, by which 
a decisive confirmation or contradiction of the optical hypothesis is rendered 
possible. For since, under the conditions which obtain in solar eclipses, the 
moon’s poles can have no libration, but the effect of libration at the east and 
west limbs is included within quite narrow limits, therefore the same protuber- 
ances must always appear at the poles in case they are caused by elevations at 
the moon’s limb; and, as regards the east and west limb, there will be, at least 
in the course of a long period of time, total eclipses with the same libration, when 
