RESULTS OF OBSERVATIONS OF COMETS I. AND II. 287 



seven times without detection. Encke after allowing for planetary 

 perturbation predicted that the comet would again pass through 

 perihelion on May 24th 1822, and an ephemeris was prepared in 

 order to enable astronomers to rediscover it at this return. On 

 laying down its theoretical track in the heavens, it was found that 

 the comet could not possibly appear above the horizon of European 

 Observatories. An ephemeris was therefore dispatched to the 

 private observatory of Sir Thomas Brisbane at Parramatta in our 

 colony, which, I believe, was the only southern observatory then 

 in existence. Nine days after the perihelion passage, or on June 

 2nd, the comet was detected at Parramatta by Riimker, afterwards 

 the director of the Hamburg Observatory, and with the imperfect 

 instrumental means at his command he succeeded in following it 

 for a period of three weeks. These observations were the only 

 data obtained at this appearance, and in the hands of Encke they 

 served for a correction of the orbit and a more accurate prediction 

 of the comet's appearance in 1825. The investigation of the 

 comet's movements thus crowned with such marked success resulted 

 in the name of Encke being permanently attached to the comet. The 

 subsequent returns of this interesting object have been calculated 

 and verified by observation on every occasion, the last being the 

 twentieth, since 1822. Five returns have been witnessed at 

 Windsor, namely in 1862, 1865, 1875, 1878, and 1888. In 1878 

 the first view of the comet was obtained at the same place, but 

 only about nine hours previously to the first observation at the 

 Royal Observatory, Cape of Good Hope. Since the death of 

 Encke the theory of the comet's movements were the special study 

 of Dr. von Asten of Pulkowa. On the premature death of the 

 latter astronomer, the comet came under the care of Dr. 0. 

 Backlund of St. Petersburg. Through the courtesy of Drs. 

 Backlund and Seraphimoff, I was supplied with an ephemeris 

 for the recent return, and I accordingly commenced a search as 

 soon as there appeared to be a probability of detecting it in the 

 evening twilight. My first attempt was on the evening of July 

 6th, but it failed. Other avocations prevented a search on the 

 following evening, but on July 8th at 6 h. 10 m. p.m. the comet 

 was found almost exactly in the place assigned to it in the ephemeris. 

 The only other notice which I have yet seen of the discovery is a 

 telegram from the Cape of Good Hope in the Astronomische 

 Nachrichten, announcing the first observation on August 3rd, or 26 

 days later than that made at Windsor. When first detected at 

 Windsor the comet appeared in the 4^ inch equatorial as a round 

 nebulous star uniformly condensed, about 1 ' in diameter, and without 

 coma or tail. Doubtless the evening twilight had much to do with 

 the non-appearance of the usual coma. From July 8th to 18th the 

 comet was shut out from observation with the 8 inch equatorial 



