IN JANUARYj FEBRUARY AND MARCH, 1858. 295 



Rumsden's eye-piece, magnifying about ninety times; the shaded 

 screen used from the 21st to 24th inclusive, was a compound one, 

 composed of one dark purple glass, and one green glass, giving a 

 greenish yellow image, the yellow predominating. On the 26th the 

 screen used was made of three green glasses, giving a greenish image ; 

 the full aperture of the Telescope was used on every occasion, and 

 with these appliances the observations were made with perfect safety 

 and comfort. The shaded screens were supplied to me by Mr. Potter, 

 Optician, of this city. 



I regret that, in consequence of my not having a Micrometer at- 

 tached to my Telescope when these observations were first made, I 

 have been unable to give correct measurements of the dimensions of 

 the spots, and of their distances from the limb of the Sun. I resume 

 the extracts from my register. 



The 27th, 28th and 29th were cloudy days, and no observations 

 could be made. 



On the 30th. This day, at 12°-20', apparent time, definition bad — 

 Sun's limb very tremulous — strong wind blowing, and atmosphere very 

 much disturbed. The spots first seen on north-eastern limb are now 

 close to the North-Western limb, parallel to it. Penumbra seen 

 above and below Nucleus of each spot, and also on the side next to the 

 limb — no Peniimbra on side next the Sun's centre — these spots are 

 much diminished in size — the small spots advanced towards the Sun's 

 centre — four Nuclei enclosed in a common Penumbra, which is very 

 faint — observed a very large spot close to South-Eastern limb, with a 

 well defined Nucleus — the Penumbra broad towards the limb, and just 

 visible only towards the Sun's centre — the upper and lower parts of the 

 Penumbra of this spot much darker than the central parts — the spot 

 parallel to the Sun's limb. This spot is marked No. 7, in the accom- 

 panying drawing. 



South-Eastern Gi'oup. 



February 1st. Definition only tolerably good — fringed look of 

 Nucleus, which is lighter towards the Sun's centre ; whilst the Pe- 

 numbra is darker towards the limb of the Sun — the Nucleus separated 

 by a light kind of band — brilliant Faculse around the lower spots. 



Februarg 3rd. Definition good — ragged look of Nucleus — light 

 colored arch in it — Nucleus not equally dark — some parts much 

 lighter than others — small spots much increased in size and number. 



February 4th. Light clouds at intervals — definition good — the 

 same ragged or streaky look of the Nucleus observed. 



