TOTAL SOLAR ECLIPSE OF JULY 18, 1860. 
357 
tolling unheeded during the eclipse, and this circumstance added much to the solemn 
grandeur of the occasion. 
The time I could spare was far too short for any exact observations of the corona ; 
however, I knew that Mr. Peitchaed, Mr. Oom, Mr. Bonomi, and other observers 
intended to make special delineations and measurements of that phenomenon, and I 
therefore confined my attention to its general characteristics. It appeared to me to 
glow with a silvery-white light, softening oflf into a very irregular outline, while from 
its general boundary shot out several long streamers. It extended generally to about 
0’7 or O' 8 of the moon’s diameter beyond her periphery. Close to the moon, and reach- 
ing not further than 2', the light was very brilliant, and several zones of gradations of 
brightness appeared to exist, but the veiy bright zones would all be comprised in a 
circle about 0‘25 of the moon’s diameter. 
The observations just recited were made in the brief interval I could afford between 
the telescopic observations, which I will now proceed to describe. In order to facilitate 
my operations, I had prepared two diagrams exactly representing the appearance of the 
micrometer lines in the telescope, and, by chance, I had made the tangential square of 
such dimensions us to include a circle precisely 4 inches in diameter, which had been 
coloured to render it more readily distinguishable, and which represented the moon. 
Four inches happened to be almost exactly the diameter of the moon’s disk on the screen 
of the heliograph ; so that, later on, the photographs and the two drawings made during 
the totality, were readily compared by the superposition of each upon each. 
On the diagrams I had painted fifteen streaks of various tints, some of which I 
beheved might resemble the colour of the prominences, and some I knew would be 
useful as a contrast, to enable the eye to form a more correct judgment. The chromatic 
scale I here insert contains a selection of the tints painted round my diagram. 
SCALE OF COLOUES WITH WHICH THE PEOMIKENCES WEEE COMPARED. 
Several minutes (probably five) before totality, I entirely removed the dark glass, and 
found that the sun’s image might be looked at without the slightest inconvenience after 
reflexion by the plain glass. I could then see in the telescope, as I had shortly before 
seen with the naked eye, the whole of the lunar disk, which appeared of a deep sepia 
brown, nearly, but not quite, black, and, to my great surprise, I perceived a luminous 
prominence, about 20° to the west of the zenith, shining with great brilliancy, although, 
on account of the plain-glass surface being then in use, the greater part of its light 
MDCCCLXII. 3 c 
