L. Boss—Tail of Comet b, 1881: 811 
TaBiE III. 
Type I. (1-v) = 11°0. | Type II. 
Point} A | ¢’ ¢-¢’ ||Point, A | ¢’ | @ | $-$’} (1-n) 
ia 
June 26) I,’ |-210 [12-9 |13°2|}+ -3]} IL’ |-179 |29°8 |31°2 | 41-4) 1-4 
L’ |-187 {14-0 |12°3 |—1-7 
June 28) I |-161| 5°6 (11-0 |4+5-4|| IL’ [189 |32°1 132° | + -7| 1-4 
IL! |-153 |27-0 29°7 |4+2°7| 1:4 
, 
daly 1 a 120 |31°3 26°5 |—4-8] 14 
July 22| 1’ |-082| 6-2| 5-7|— -a|| IT’ |-057|24-9 12° |—13-| 1-4 
16° |— 9-| 1-0 
21: |— 4} *6 
A value of 0°4 for (1—y) would give a fair = ijeeont nose to the 
tail of Type If as observed on July 22. The agreement of the 
observed and the computed values of g for the tail of the first 
type is very satisfactory. The deviation of five degrees on 
June 28 might easily be attributed to errors of observation on 
an object which was so excessively faint; and it is quite prob- 
able that the location of the end point was somewhat influenced 
by the general direction of the tail nearer the nucleus where it 
was brighter. Such an influence would tend to make the ob- 
served value of yg too small. The two values of 9’ best deter- 
mined for Type [ are the second and fourth of the table; and 
these both indicate that a smaller value of (1—y) should have 
than four or five degrees. This would make any value of (1—p) 
Am. Jour. Scr.—Tamp Series, Vor. XXII, No. 130.—OcToner, 1881. 
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