370 REPORT— 1850. 
coloured glasses, the observer alternating the colours, which should 
be as dissimilar as possible, such as red and green? 
Whether they are seen when the telescope is out of focus? 
Whether they are seen when the eclipse is projected on a screen? 
The drawing out of the beads into threads when very near junc- 
tion ; and whether they waver and change, and the number of them. 
Whether before and after the formation of the threads the moon’s 
dark disc is elongated towards the point of contact ? 
The beads are ascribed by some to lunar mountains. What 
mountains exist at that part of the limb? 
The exact interval of time between the first formation of beads 
and the first complete contact, and that between the last complete 
contact and the last disappearance of beads (or other irregularities 
in or about the cusps), should be determined. ; 
The remarkable fact of a recurrence of cusps, and the possible 
explanation of it, should be attentively considered. 
In reference to the phenomena of the corona, and their possible 
explanation, the observer is referred to Professor Powell’s papers in 
the Memoirs of the Astronomical Society, vol. xvi. p. 301, “On 
Luminous Rings round Shadows,” and vol. xviii. p. 69, “ On Ivra- 
diation.” 
Aprrnpi1x No. II. 
It is recommended to observers who may devote themselves 
especially to the phenomena of the rose-coloured prominences :—- 
1. Immediately before the total obscuration, to watch for the ap- 
pearance of the prominences on all parts of the sun’s limb, but par- 
ticularly at the part just about to be eclipsed by the moon’s limb ; 
and, the moment that the sun’s bright edge is eclipsed, to watch in 
the direction of the moon’s advance for any such prominence ; to 
note mentally its form, and particularly the proportion of its height 
to its breadth at the base, which may be afterwards recorded in a 
sketch ; and ¢o make quite sure whether or not the moon gradually 
eclipses it. 
2. In like manner, and with the same view, to direct the second 
scrutiny (immediately after the previous one) to the diametrically- 
opposite portion of the moon’s limb, watching for the summits of 
any prominences, and whether they enlarge as the total eclipse 
proceeds. 
. 8. In the third place, the observer having satisfied himself on 
the two previous points, will carefully examine the moon’s limb all 
round, and may now record, on the previously prepared circular 
diagram, the positions of any such prominences round the moon’s 
limb. Let this be done in the first instance without regard to 
their form or size, but only with regard to their distribution round 
