[A.NNALS N. Y. Acad. Scr., Vol. XV, No. 3, pp. 217-297, Nov. 30, 1904.] 



RESEARCHES AS TO THE IDENTITY OF THE 



PERIODIC COMET OF 1889-1896-1903 



(BROOKS) 



WITH THE PERIODIC COMET OF 1770 



(LEXELL). 



Charles Lane Poor. 



Contents. 



PAGE. 



Introd uction 219 



Part 1 226 



A. Preliminary Correction to the Elements 227 



Computation of Perturbations 228 



Difficulty of Correcting Elements 232 



Perturbations by Venus 233 



Approximate Elements 234 



B. Observations of the Comet 234 



First Appearance 234 



Second Appearance 237 



Third Appearance 238 



C. Comparison of Observation with Theory 239 



Ephemeris 239 



Weight of Observations 239 



Comparison Stars 242 



Formation of Normal Places 243 



Perturbations 245 



D. Definitive Correction to the Elements 247 



Equations of Condition 248 



Normal Equations 251 



Remaining Errors 252 



Definitive Elements 254 



Indeterminate Solution * 255 



Part II : 258 



General Statement 258 



Perturbations 1889 to 1886 258 



Transformation to Jupiter as center 264 



Method of LaPlace 264 



Extension of Method 265 



Formulas for Transformation 268 



217 



