THE QUAETERLY 



JOURNAL OF SCIENCE. 



OCTOBEE, 1870. 



I. THE ECLIPSE OF AUGUST 7, 1869.— « ANVIL" 

 PKOTUBEEANCE. 



By W. S. Gilman, jun., New York. 



Those who observed the solar eclipse of last August with a sizeable 

 telescope will not soon forget the startling effect produced by the 

 appearance of the large oval protuberance on the western limb of 

 the moon. We were unusually favoured as to atmosphere at our 

 station near Sioux City, Iowa, and when in addition to this it is 

 stated that our observations were made by the aid of a 4-inch re- 

 fractor — one of Mr. Alvan Clark's best — it will not seem strange 

 that the details about to be recorded were so readily obtained. 



The "anvil" protuberance, for such the object is recorded in 

 my notes, was seen by one of our party several moments prior to 

 the totality. 



Several months' study of the sun's surface had prepared me to 

 expect the more remarkable protuberances in the southern hemi- 

 sphere, and having selected the south-western quadrant as an 

 especially favourable locality, from the presence of faculous ridges 

 near the limb two days prior to the eclipse, the bright " anvil "- 

 shaped mass instantly attracted my attention. Its extraordinary 

 brilliancy enabled me afterwards to keep it in view when a con- 

 siderable crescent of the reappearing sun had rendered the corona 

 invisible. 



A hasty glance at other portions of the moon's limb satisfied 

 me that the " anvil " protuberance possessed greater interest than 

 any other, and I therefore devoted my whole time to its considera- 

 tion, except so much as was employed in obtaining several outline 

 sketches of the corona. 



In a forecast of the probable positions of protuberances, which 

 I made on August 5 (see Fig. 1), the double prominence at A 

 occupies very nearly the position of the object under discussion. In 

 Fig. 2 we have the appearance of the sun's disc on the same day, 

 and near that part of the limb subsequently occupied by the 

 " anvil," we notice a cluster of bright faculous spots. It was the 



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