76 THE POPULAR SCIENCE MONTHLY. 



from our view, it cannot surely be considered blameworthy if astrono- 

 mers have directed their attention to that without and have endeav- 

 ored to connect the behavior of sun-spots with the positions of the 

 various planets. Stimulated no doubt by the success which had at- 

 tended the labors of Schwabe, an English astronomer was the next to 

 enter the field of solar research. 



The aim of Mr. Carrington was, however, rather to obtain very 

 accurate records of the positions, the sizes, and the shapes of the 

 various sun-spots than to make a very extensive and long-continued 

 series of observations. He was aware that a series at once very ac- 

 curate and very extended is beyond the power of a private individual, 

 and can only be undertaken by an established institution. Neverthe- 

 less, each sun-spot that made its appearance during the seven years 

 extending from the beginning of 1854 to the end of 1860 was sketched 

 by Mr. Carrington with the greatest possible accuracy, and had also 

 its heliographic position, that is to say its solar latitude and longitude, 

 accurately determined. 



One of the most prominent results of Mr. Carrington's labors was 

 the discovery of the fact that sun-spots appear to have a proper mo- 

 tion of their own those nearer the solar equator moving faster than 

 those more remote. Another was the discovery of changes, apparently 

 periodical, affecting the disposition of spots in solar latitude. It was 

 already known that sun-spots confined themselves to the sun's equa- 

 torial regions, but Mr. Carrington showed that the region afiected was 

 liable to periodical elongations and contractions, although his ob- 

 servations were not sufiieiently extended to determine the exact length 

 of this period. 



Before Mr. Carrington had completed his seven years' labors, celes- 

 tial photography had been introduced by Mr. Warren De la Rue. 

 Commencing with his private observatory, he next persuaded the Kew 

 Committee of the British Association to allow the systematic photog- 

 raphy of the sun to be carried on at their observatory under his 

 superintendence, and in the year 1862 the first of a ten years' series 

 of solar photographs was begun. Before this date, however, Mr. De la 

 Rue had ascertained, by means of his photolieliograph, on the occasion 

 of the total eclipse of 1860, that the red prominences surrounding the 

 eclipsed sun belong, without doubt, to our luminary himself. 



The Kew observations are not yet finally reduced, but already sev- 

 eral important conclusions have been obtained from them by Mr. De 

 la Rue and the other Kew observers. In the first place the Kew 

 photographs contirm the theory of Wilson that sun-spots are phenom- 

 ena, the dark portions of wliich exist at a level considerably beneath 

 the general surface of the sun ; in other words, they are hollows, or 

 pits, the interior of which is of course filled up Avith the solar atmos- 

 phere. The Kew observers were likewise led to associate the low 

 temperature of the bottom of sun-spots with the downward carriage 



