258 The Great Comet of 1861. 
their places were filled by new ones. Latterly, two, at most, 
could be seen at one time. It is quite important to remark that 
the successive envelopes resembled their predecessors not only 
in their general aspect but quite closely in the details of their 
structure; the luminous jets not issuing at random from all 
points alike of the nucleus, but continuing to follow a nearly 
‘similar course at each new discharge from its surface 
e most natural inference from this would seem to be that the 
the gpposeanth of witnessing them, had they existed, was very 
favorable, as the sectors were well displayed. 
e nucleus was throughout brilliant, and, to appearance, 
solid, with a diameter of from 2” to 3”. ee 
The disposition of the nebulosity in the part of the tail con- 
tiguous to the head was nearly uniform throughout; the axial 
darkness being scarcely distinguishable, excepting on one occa- 
sion, July 3d. : 
The following positions haye been derived from comparisons 
with neighboring stars. 
Cambridge mean 
1861. solar time. a 6 , 
July 2, 8h 28m 3gs 8h 37m 435,99 462° 51/171 
8, 8 oI $a 9 49 15°85 66 6 15°3 
3, 10 39 652 9 56 6°58 66 16 
4, 10 89 18 It 2 F748 66 53 
5, 32-0 °26 1t 67-9 367 66 3 
6, 9 17 39 ie ol = OG 64 51 
8, 10;.20° 8 18 21.36 06 61 46 
9, 10 40 47 18: 87. ST. -88 60 21 
10, 9 39 12 138 49 26°80 59 «9 
39... 11. BT. 47 14 8 0°59 56 54 
is, 0 47 286 14 18 59°24 56 52 
The nucleus admitted of ver _ observations ; 
is a curious fact that it seabed 4 quite pmo by meaus 
proper comparisons with neighboring stars, to obtain 
alee of terrestrial longitudes of the principal points at whi 
