Mayer.] ^'-^'^ [Oct. 1, 



Plate 43 shows that the circular outlines of umbra and penumbra have 

 changed into elliptical boundaries, the direction of the longer axis being 

 N. W. and S. E. The umbra has widened in this direction A", or 1796 

 miles, and has, in the transverse direction, narrowed its breadth 5. "5, or 

 2357 miles, while the outward projections of the umbra (which can be 

 identified on ijlate 4) have become greatly lengthened. 



Photograph No. 15, of the series, shows this spot bisected by the limb 

 of the moon. 



All the photographs show a gradation of shade from the border of the 

 sun inwards. This shading of the source of light is due to the absorp- 

 tion of the peripheral rays which necessarily pass through a greater thick- 

 ness of the dense solar atmosphere, than those which emanate from the 

 central portion of the disc. 



"VVe also observe on the photographs close to the limb of the moon, a 

 bright glow like that of early dawn, which on plate No. 11 can be dis- 

 tinctly traced to 18" beyond the limb of the moon. If this phenomenon 

 cannot be explained in mode and in measure by diffraction, it must be 

 due to a lunar atmosphere, though it is difficult to reconcile its existence 

 with the inappreciable refractive effect on small stars, and especially 

 on double stars, when occulted by the moon. 



I will not attempt at present a complete description of the plates ob- 

 tained during totality. I merely refer you to the diagram which I have 

 prepared, and call your attention to those of the most remarkable protu- 

 berances. These protuberances ^ have numbered from 1 to 12, going 

 from N. through E. to N. 



No. 4, on the eastern limb of the sun, has the appearance of an eagle 

 with outspread wings resting on the trunk of a tree which leans towards 

 the north, on plate No. 27, where the base of the protuberance is cut off by 

 the advancing moon, the resemblance to an eagle on the wing is perfect. 

 The form of this object indicates instability, and impresses one with the 

 idea that it is a great travelling whirl of flame, the direction of whose 

 rotation — as indicated by the position of "the wings" and the projection 

 of one on the other — is retrogade or in the same direction as the hands 

 of a watch. I have examined with care the successive photographs of it, 

 and although at first I thought the last impression differed from those 

 preceding in that the wings had become longer and more in a line with 

 each other, yet, on subsequent examination, I could not really decide 

 that a perceptible motion had taken place during the time of totality. 



The position-angle of the N. side of the base of this object is OC 25'; 

 its height is 1' 22", or 33,700 miles, and the spread of the wings is 9° 31', 

 or 70, h 00 miles. 



On the western limb of the sun we see the remarkably large and mas- 

 sive protuberance No. 8. It is shaped like an albatross head, with the 

 beak and under-side of the head resting on the periphery of the moon. 

 On a photograph taken at Ottumwa, Iowa, just before the sun came out, 

 this protuberance had the exact appearance of an albatross head, with 

 the beak open, holding a rounded mass between the extremity of the 

 jaws. It lies between the position-angles of 210'^ 13' and 245° 40'; its 



