Mat 11, 1883.] 



SCIENCE. 



389 



power of about 200 diameters was used on 

 each occasion for making the sketches. 



Fig. 1 shows the comet on Feb. 1, 1883, at 

 about the time of meridian transit, or 9h., 



Fia. 1. Feb. 1, 34, 1S83 



Washington mean time. The nucleus which 

 I first saw in anj- degree ' separated,' on the 

 morning of Oct. 7, 1882 (its entire length at 

 that time being about 25") , has now stretched 

 out into a fine straight line of liglit, with three 

 quite bright and stellar-lilsie points of conden- 

 sation. No micrometer measures were made ; 

 but, from a rough estimate, the distance be- 

 tween the two preceding points was about 35", 

 and the distance from the middle to the follow- 

 ing point about 42", the total length of the 

 nucleus proper being about 80." The middle 

 point was the brightest. The head shows no 

 very definite outline, but on the south side 

 it is somewhat brighter and more sharply de- 

 fined than on the north. 



Fig. 2 shows the comet on Feb. 23, 1883, 

 just after meridian passage, or about 8h., 

 Washington mean time. I can see but little 

 change in the appearance of the nucleus since 

 the first of the month, or, indeed, since the 

 first part of December, except a gradual dimi- 

 nution in brightness. Three bright points are 

 still visible. The middle one is brightest, and 



Feb. 23, 34, 1883. 



and the point following is the faintest. The 

 light seems to be more concentrated near the 

 preceding end. The position angle of the fol- 

 lowing jjoint from the preceding was 76.5° ; 

 but the poor seeing and the increasing moon- 

 light rendered it impossible to make any ac- 

 curate measurements of the distance between 

 these points. 



Fig. 3 gives the appearance of the comet on 

 Feb. 27, 1883, at about 8h. 30m., Washington 

 mean time. The seeing was remarkably good, 

 and the nucleus was examined with magnify- 

 ing powers of 200 and 383 diameters. "Four 

 bright points were seen distinctlj', and a fifth 

 {following) suspected . Numbering these points 

 of condensation in their order from the pre- 

 ceding end of the nucleus, 3 is decidedly 

 the brightest, 2 next, 4 next, and 1 the faint- 

 est. 



Professor Hall made a number of measure- 

 ments of the distances of these points, and he 

 has kindly furnished me with the following re- 

 sults of his observations : — 



2 to 3 = 34.5" 



2 to 1 = 48.1" 



3 to 4 = 22.3" 



about equal to a star of the twelfth magnitude ; 

 the point preceding is a little fainter than this ; 



Fig. 3. Feb. 2T, 36, 1883. 



Position angle of the line joining 1 and 4 = 

 78°. This gives for the distance between the 

 extreme points V 44.9". Using a value 

 [0.45885] for the logarithm of the distance 

 from the earth, interpolated from Professor 

 Frisby's ephemeris, the apparent distance be- 

 tween our extreme points of condensation is 

 135,000 miles. If, however, these points lie 

 on a line pointing from the sun, as this line 

 makes quite a small angle with the line of sight 

 at the time of observation, the real distance of 

 our two points is about three times this value, 

 or, roughly, 400,000 miles. 



The comet was last observed on the 3d of 

 March, but it is hoped that further obser- 

 vations can be obtained after the moon has 



W. C. WiNLOCK. 



