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 XLIV. Intelligejice arid Miscellaneous Articles. 



ON A LATE SOLAR SPOT. 

 To the Editors of the Philosophical Magazine and Journal. 

 Gentlemen, 



HAVING received on the 9th instant a letter from Sir J. W. 

 Lubbock, informing me that he had observed a spot on the 

 sun on the 19th of November last year, very similar to that which I 

 took the liberty to notify in the Philosoj^hical Magazine of last month, 

 I beg to be allowed to make the observations, which he places at my 

 disposal, public through the medium of your pages ; as well to fur- 

 nish another satisfactory ))roof of what appears not to have been 

 sufficiently noted or credited, in general, as to acknowledge the 

 priority of his observation of the fact in question. Comparing the 

 ajipearanccs of the two spots. Sir J. W. Lubbock says, — 



" Like yours it was seen as one with the naked eye by my children 

 and by my labouring people, with whom I happened to be, and who 

 called my attention to it. Like yours it was seen as two spots in a 

 telescope, with a immber of smaller ones under it. I enclose a copy 

 of a drawing I made at the time. Like yours it was seen through a 

 fog, the sun's disc being of a blood-red colour. It would seem that 

 there must have been about sixty-seven days intervening between 

 your observation and mine ; and as the sun revolves about its axis 

 in 25'4 days, I presume either the spot must have changed its place, 

 or it was not the same." 



Though the sketch referred to has certainly some general resem- 

 blance to the spot of the 25th of January, the central nuclei of the 

 latter were much more oblong, or rather stripe-shaped ; and the 

 aggregation of spots and shallows on one side of these formed the 

 aspect of a crescent, or segment of a circle, not unlike an eyebrow, 

 relative to the others when viewed through a telescope. Still such 

 transmutations might be expected to have occurred between No- 

 vember and January in the same spot. Had the position been nearly 

 the same, and the period of revolution completely accorded, the spots 

 might have been considered identical. 



I had some difficulty in recognizing the spot of the 25th of January 

 after its reappearing, which I first noticed on the 14tli of February. 

 As it advanced, however, I think I found sufficient similarity of fea- 

 tures to identify it, the time also agreeing with the period of appa- 

 rent rotation. The whole seemed contracted, and the various umbrre 

 had become conjoined more or less, the arched cluster also forming 

 a junction with the central penumbra. Some of the smaller spots 

 had run into one, and the two long central spots had also united. 

 A detached spot west of these had probably broken out since the 

 disapj)earance. Such was its aspect on the 22nd of February; un- 

 favourable weather and other circumstances prevented my insi)ecting 

 it oftener. PVom a conversation I had lately with my friend Mr. J. 

 Adie, optician, who had also seen the spot with the naked eye, I am 



