ASTRONOMY. 149 



epbemeris computed directly I'roiii the elenieiits was — •l"'.-t; + '^', corre- 

 sj)oiidiiis to a letardatiou of the i)erihelion time of about two days. 



Comet Gibers, orii^iiially discovered by the celebrated Dr. Gibers on 

 JMarch C, 1815, was picked up by Brooks on August 24, 1887, inde- 

 dendently of Ginzel's epliemeris. Bessel, who made a discussion of 

 the earlier observations, predicted a return to perihelion on February 

 1), 1887, and Dr. Ginzel, rediscussing the orbit in a very elaborate 

 manner, found the most probable date of perihelion to be Decem- 

 ber 17, 1880, with an uncertainty of l.G years. Perihelion actually 

 occurred on October 8, 1887. Especial interest attaches to this comet 

 as the third member of the group of comets having a period of about 

 seventy-live years (Halley's, Pons', and Gibers'), which has returned 

 to perihelion in conformity with i)redictiou. Kammermann, atGeneva, 

 described it on August 29, 1887, as a bright 7.8 niagnitude, with a faint 

 tail. There seems to be no reason for supposing that it has lost any- 

 thing of its light-giving power since its previous appearance in 1815. 

 The last observation at this return was nuule at the Lick Gbservatory 

 on July 5, 1888, when the theoretical brightness was less than one- 

 tenth that at the time of discovery. 



Comet Tempcl. — The comet discovered bj- Tempel on July 3, 1873, and 

 found to have a i)eriod of live and one (juarter years, was observed at its 

 return in 1878, but escaped observation in 1883 when it was due at peri- 

 helion on November 20, Tiie conditions of visibility seem to be even 

 worse for the return of 1880, the comet remaining too near the sun, 

 while the circumstances of the return in 181)1 are but little diflereut 

 from those of 1883. 



Comet ^yinn€clie. — You Ilaerdtl has rediscussed the motion of Win- 

 necke's comet, making use of observations at a later return than Gp- 

 l)olzer could employ in 1880. The object was to detect, if possible, any 

 increase in the mean motion similar to that exhibited by Eucke's comet, 

 though not sensible in Faye's comet, possibly owing to its great perihe- 

 lion distance. Ue finds no acceleration whatever of the mean motion, 

 the actual figures indicating rather a slight retardation, but far too 

 snuill to justify any conclusion other than absence of change in the 

 mean motion and length of period. 

 Comet 1880 VIII; 

 =Comet c 1887. 



1880. ~ 



Comet 1887 I: 



=Coiiiet a liS87. 



=Tlio grout .soiitlio.rn comet. 



Discovered by J>arnard on January 23, 1887; last 

 observed on May 22, 1887; i>erihelion November 28, 



A cable dispatch from Dr. Thome, the di- 

 rector of the Cordoba Observatory in South 

 America, announced his discovery on Jan- 

 uary 18, 1887, of a large comet, or rather the tail of a large comet, faint 

 iind illusory in the twilight and mist of the horizon. From later infor- 

 mation it a])peared that the comet was seen at Blauwberg, near Cape 

 Town, on the same evening, by a farmer and a fisherman, and a day or 

 two later it was seen at several i)laces in Australia. Dr. Thome was 



