COMET OF 1889-1896-1903. 293 



ances by Jupiter in 1886 and in 1837; that the ;z's for this 

 comet and for Lexell were nearly the same and that, therefore, 

 Tisserand's criterion was approximately satisfied. The effect of 

 the disturbance in 1886 was determined with considerable accu- 

 racy, but the effect of the disturbance in 1837 could not be 

 directly calculated, and before that date the uncertainty of the 

 path of the comet became considerable. Schulhof further 

 showed, upon suppositions which are in accord with the known 

 elements of the body, that it was possible for Comet Swift to 

 have been within the sphere of Jupiter's activity at the same 

 time that Lexell's comet was known to have been within that 

 sphere in 1779. Yet Schulhof only concludes that the identity 

 of the two comets is possible. 



The evidence in support of the supposed identity of Comet 

 Swift (1895, II) with that of Lexell (1770) is stronger than 

 that which can be brought forward in support of the suspected 

 identity of Comet Brooks (1889, V) with Comet Lexell. 



Conclusions. 



{a) The results of this investigation go very far towards 

 proving the non-identity of Comets Brooks and Lexell, al- 

 though they are not conclusive and admit the possibility of 

 such an identity. 



(d) The computations upon which Chandler based his con- 

 clusion of identity of these two bodies are shown to be in- 

 sufficient on account of the omission of certain important 

 perturbations. 



(c) Any conclusions as to the path of the comet previous to 

 1886 must depend to a large extent upon the perturbations suf- 

 fered by the comet while in the immediate vicinity of Jupiter and 

 due to the elliptical figure of that planet. In any further dis- 

 cussion of the path of this comet these figure perturbations 

 must be most carefully investigated. 



