ASTKONOMY FOR 1889, 1890. 141 



ently inclosing the whole group (A. K, 2914). I have from the first 

 carefnllj^ looked for a nebulous connection. Under unfavorable circum- 

 stances the tails of B and G might be imagined to be a connecting neb- 

 ulosity, but the tail of E falls short of A, and that of C does not nearly 

 reach B. Each comet is in appearance absolutely independent of the 

 other. The tails of all three have lain in the line of the nucleus of A, 

 and therefore have not sensibly deviated, from the position-angle 241°." 



" On August 4, two other companions were detected with the great 

 telescope, one of which was measured, the other being too elusive to 

 set the wire on. I have numbered these four companions B, C, D, E, 

 in the*order of increasing right ascension, A being the larger comet, D 

 and E being the two last discovered. D has been seen several times 

 since the moon withdrew, but has always been too faint to observe. It 

 has not sensibly changed its position. E has only been seen once. Its 

 position angle referred to C would be the same as that of D, and its 

 distance twice as great. Four or five other nebulous bodies observed 

 near the comet, August 2, have not since been seen, and were probably 

 nebulous. 



''The results of the observations of the two brighter companions are 

 extremely interesting. Measures of B have been made on eighteen, and 

 of C on seventeen nights. These two have almost exactly the same 

 position-angles, which have been sensibly constant. Their distances 

 from the main body have, however, been increasing. At the last ob- 

 servations, B seems to be stationary, the distance from A remaining 

 constant, while C continues to recede." 



Mr. Chandler's investigation of the orbit of this comet has devel- 

 oped a strong probability that it is identical with a comet discovered 

 by Messier in 1770, often called Lexell's lost comet, because that 

 astronomer calculated that it was moving in an elliptic orbit with a 

 l)eriod of about 5J years, though it was not seen afterwards. It is now 

 well known that this was due to the fact that at the return in 1776 

 its position was such as to render any observation impossible, and 

 before another return could take place the comet made in 1771) so 

 close an ai)proach to the planet Jupiter as completely to change 

 the nature of the orbit. Mr. Chandler finds that Brooks's comet also 

 made a near approach to Jupiter, so near, in fact, on May 20, 1886, that 

 it was only about nine diameters of Jupiter distant, or only a little 

 outside the orbit of his third satellite. Calculation of the elements of 

 the comet orbit before this appulse leads to the conclusion that they 

 present a great similarity to those of Lexell's comet after its approach 

 to the planet in 1779, rendering the probability great that the bodies 

 are identical. Mr. Chandler shows that no similar serious disturbance 

 will occur again until 1921, so that appearances may be looked for in 189(5, 

 1903, 1910, and 1917, at each of which return the condition of visibility 

 will be favorable, giving opportunities for farther investigations into 

 the motions of this interesting cornet, which, it appears, narrowly 



