530 IOWA ACADEMY OF SCIENCE Vol. XXVI, 1919 



Prof. C. W. Crockett, of Rensselaer Polytechnic Institute, re- 

 ports (see ibid) from observations at Juliette, Georgia: "A sheet 

 was spread horizontally, the corners being tacked to stakes driven 

 in the ground. The observers reported that the bands were about 

 the width of a man's hand, wavy and indistinct, and that it was 

 impossible to count them." 



PHOTOGRAPHS OF THE CORONA 



The three eclipse parties agreed upon a definite program. A 

 break circuit chronometer owned by Professor Pettit operated three 

 sounders, one in each shack. Prof. P. F. Whisler, of Illinois Col- 

 lege, Jacksonville, Illinois, acted as official timekeeper. Beginning 

 five minutes before the computed time of totality, he called each 

 minute in the reverse order, as, five, four, three, two and one. Miss 

 Vera Gushee, of Smith College, at the appearance of the corona, gave 

 the signal to start by striking a large barrel with a hammer. This 

 was the zero of our exposure time. At this signal, Professor Whis- 

 ler called out the half beats of the chronometer, as zero, and, one, 

 and, two, and ... In our practice, I had been stopping on the 

 eighty-sixth second, although our computed time gave us eighty- 

 eight seconds. 



With this program, I secured six photographs of the corona, one 

 with the five-inch photographic doublet and five with the eight and 

 one-fourth inch equatorial, which was provided with a photographic 

 lens of 120 inches focal length by the John A. Brashear Co., and 

 the regular driving clock. The photographic doublet was attached 

 to the tube of the equatorial. 



The photographs with the doublet and equatorial were taken 

 simultaneously with forty seconds exposure, from the eighteenth 

 to the fifty-eighth second of our program. The five-inch negative 

 is badly overexposed. The corona merges into the sky effect and 

 the prominences are reversed, that is, they are light in the negative. 

 A slender halo, also reversed, standing out away from the moon's 

 disc, connects the top of two prominences which are about sixty de- 

 grees apart. The corona is distinctly triangular in shape. The long 

 eastern streamer forms the vertex of an isosceles triangle and the 

 western streamers diverge to form the base. This is quite unusual. 

 Most of the previous eclipses have shown a quadrangular or irregu- 

 lar four-rayed star shape. When we consider the position of the 

 three great prominences and the fact that the longest streamers were 

 directly above them, it seems not impossible that there is some 

 connection between the prominences and the shape of the corona. 



