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spot, ill which the secondary penumbra had been plainly 

 visible, and had been observed by him to consist of a fine net- 

 work of bright lines. The penumbra was strikingly striated, 

 and the middle of the nucleus had been occupied by a bright 

 spot detached from the penumbra at first, but afterwards 

 joined to it, as the spot began to close up, by one of the pro- 

 jecting spurs usually observed to occur in decaying spots. 

 For the purpose of the observations a trough filled with 

 sulphate of indigo was placed in the cone of rays coming from 

 the large mirror of a Newtonian reflector of seven inches 

 aperture, before they reached the eyepiece. The sun's image 

 was a deep red colour, but the definition was very good. 



Professor Clifton suggested that the unusual visibility of 

 the secondary penumbra in this case might arise from its being 

 so coloured as to be rendered more visible than usual by the 

 use of the sulphate of indigo. 



June 27th, 1861. 



Mr. Baxendell read a Paper entitled " Observations of 

 Comet I, 1861." [This Paper was afterwards read at the 

 Ordinary Meeting of the Society, held on the 1st October, 

 1861.] 



Mr. Baxendell also read a note " On a Solar Spot of 

 Long Duration." 



At the last meeting of the Section I exhibited a sketch 

 made on the 24th April, 1861, of a solar spot in which the 

 secondary penumbra had been seen with unusual distinctness* 

 This spot has since twice crossed the visible disk of the sun, 

 and has had a term of existence considerably above the ordi- 

 nary average. It was first seen on the 17th of April, near 



