ISGO.] ~^''^ [>rayor. 



[Prof. ]\[ayer lieve exhibitod copies on plate-glass, taken from the origi- 

 nal negatives with an orthoscopic lens, and also coijies on paper enlarged 

 to abont five inches in diameter. A large diagram showed more dis- 

 tinctly to the members the forms and positions of the protuberances.] 



Photograph No. 4, taken 2.8 seconds after observed contact, shows a 

 depression in the sun's limb at the position of first contact, and from 

 this depression shoots into the sun a high lunar mountain, whose posi- 

 tion measured from the IS. point of the cusp, is about ^th of the distance 

 to the N. point of the same. Mr. AV. S. Gilman, Jr., of New York, 

 who observed with exquisite skill at Sioux City, Iowa, informed me that 

 he obtained his time of first contact by seeing this mountain peak thrust 

 itself into the sun's limb before a fiattening occurred from the contact of 

 the lower general surface of the moon. 



[Prof. M. here gave an account of the geometrical methods iised to 

 determine the times and angles of contact from measurements on the 

 cusps of the sun.] 



The time of first contact deduced from approximate measures on two 

 plates gave !13h. 2m. ■1.24s., Burlington Sidereal Time, which is 1.1s. be- 

 fore contact as observed by Prof. Coffin, and 0.1s. before Dr. Gould's 

 observation. From measures on another plate we deduced 13h. Im. 

 .^7.3s., which is 4s. before contact as observed by Dr. Gould, and Y'\,th of a 

 second after contact as determined by Prof. Young with his new spec- 

 troscopic method of observation. 



Measures on plate No. 8 gave for the position-angle of 



first contact —70° 48' 



Computed angle — 71° 



Difference —0° 12' 



Plate 41 gave for position-angle fourth contact 108° 34' 



Computed angle 108° 0' 



Difference +0o 34' 



Sixteen spots were visible on the sun's disc during the eclipse. Two 

 large spots, one in the S. W. quadrant, the other in the N. E., are beauti- 

 fully defined on the photographs. Near the eastern point of the sun's 

 limb is a remarkably beautiful and characteristic spot, greatly fore-short- 

 ened from its position so that the penumbra has disappeared on the west 

 side of the umbra, against which rests the large bright faculae, which 

 enclose the spot, while one bridges over the spot in a N. E. direction and 

 seems to divide it into two portions. I here exhibit drawings of the spot 

 in the S. W. quadrant which show the rapid changes which took place 

 in the foim and dimensions of this spot in Ih. ."iO.Sm., the interval be- 

 tween the times of taking the jilates from which they are drawn. 



On plate 4, we see the umbra and penumbra of a general circular out- 

 line, with an intensely white projection into the N. W. point of*the 

 margin of the penumbra. The mean diameter of the umbra is G,GJO 

 miles. 



