W. A. Norton on the Dimensions of Donati’s Comet. 61 
On comparing the calculated positions of particles which left the re- 
gion of the nucleus at the same instant, and with the same initial velo- 
city, but were afterward subjected to different degrees of accelera- 
tion, from the action of the sun, it appears that they are all distrib- 
uted nearly along a right line, which of indefinitely produced would 
pass near the nucleus. is result is illustrated in fig. 1; in which 
the lines traversing the tail in directions radiating from the nu- 
cleus represent the lines of particles that left the nucleus at the 
several dates above specified. When the calculated positions 
are plotted upon a large chart, the distribution is found to be 
very nearly rectilinear. The same fact appears on determining 
by calculation the relative positions of the several lines connecting 
the computed places of the particles in the plane of the orbit. 
The following table contains the computed codrdinates of the 
Positions of particles which left the region of the nucleus with 
Part. leaves nucleus. Force, 7 r R. Ase. 
ee eee 
Dd. “ M 
Oct. 26043 |: R, 2°73 16 33 0 57,076,000 
“ “ R. 
a 22 23 oN. 
| Sept. 29-7523 R, 1°82 16. 1 40 39,406,000) 214 I ta 
5 ie R, 1-213 | 16 8 47 | 58,717,500) 
2 R, 0°455 | 16 17 50 | 57,892,600 
. - R & Axo | 16 23 30 | 57,329,000/212 45 40|20 38 20 N. 
. a o3 16 27 16 | 56, 3 800 212 31 20/20 18 20 N, 
“ &‘ ? : 
| A, 0455 16 28 ; 
Sept. 24-360 1°82 12 28 20 | 68:066,600\218 25 20/31 35 fo N. 
aia R, 1-213 | 13 HM : pine t 
& &% : y 27 2 E 
. 5 Re Pb Z 54 50 | 60,554,000\214 17 20124 3 fo N. 
x ~ A, 15 39 10 | 58,579, 
Sept. 19 049 R, ode. 5 59 36 | 78,882,000)221 re 55/43 = ag N, 
= . Rid Asso| 11 51 0 | 64,773,000)215 34 20/29 2 N. 
a ~ ‘A. 0-303 | 13. 8 13 | 62,238,000)214 32 4oj2 36 5 N. 
pt. 13-8: A, 0455 | 13 53 Be | Gosoqoooiar5 50 40135. 14 10 N 
Sept. 13-834 R& A=o| 7 4 } 3 6 5 
. s 0-303 | 10 7 10 | 65:303,000)214 530 oN. 
1 “y « 1 A’ 96455 | IL 25 30 | 63:396,000|214 21 50\26 37 40 N. 
Oct. 50776 (nucleus) NT 16 38 0 | 56,173,500\212 5 3019 39 20 N, 
