588 



NATURE 



[Oct. 20, 1887 



€inguinus) from the Caves of Adelsburg, presented respectively 

 by Prof W, H. Corfield, F.Z.S. and Dr. E. Rickards ; a 

 Spotted Salamander {Salamandra maculosa), European, pre- 

 sented by Mr. Alban Doran ; a Gorilla {Anthropopiihecus 

 gorilla 6), three Pluto Monkeys {Cercopithtctis pluto), an 

 Erxleben's Monkey ( Cercopithectis erxlebeni 9 ) from West Africa, 

 deposited ; two Coypus {Myopotamtis coypus), born in .the 

 Gardens. 



OUR ASTRONOMICAL COLUMN. 



New Minor Planet. — A new minor planet, No. 270, was 

 discovered by Dr. Peterson October 13. 



Olbers's Comet. — The following corrected elements and 

 ephemeris for this object are by Herr O. Tetens {Astr. Nachr. 

 No. 2806) :— 



T = 1887 October 8-4938 Berlin M.T. 



Mean Eq. 1887 'o 



X = [9-854835] r sin {v + 237 35 31) 

 y = [9'97235i] ''sin (v + 168 39 22) 

 z = [9'89i623] r sin {v + 95 54 3) 



Ephemeris for Berlin Midnight. 



1B87 



Nov. 



log A. 

 0-2795 

 0-2831 

 0-2875 

 0-2924 

 0-2979 



0-3037 



The brightness on October 26 will be i -48, and on Novem- 

 ber II, 1-20 ; that on August 27 being taken as unity. 



Southern Double Stars. — A welcome addition to the 

 still somewhat scanty supply of observations of southern double 

 stars is contained in the Monthly Notices for June 1887, which 

 furnishes a series of measures of stars in relative motion recently 

 made at the Sydney Observatory, special attention having been 

 paid to the binaries a Centauri and 7 Coronae Australis. The 

 mean of eighteen measures of position-angle and distance of the 

 components of a Centauri gives for the epoch 1886-47 : angle = 

 202^-3, distance =: i5"'io ; whilst the mean of four measures of 

 difference of R.A. and of declination of the components gives 

 for 1886-55: angle = 201° -o, distance = i4"-87. Referring to 

 Monthly Notices, vol. xlvi. p. 340, we find that for the former 

 epoch the computed places are as follows : — 



Downing-Elkin orbit-angle : 

 Powell orbit-angle 



2026, distance = 15-11. 

 201 -8, distance = 15 '26. 



These orbits give for the periodic time of a Centauri the values 

 76 years and 87 years respectively ; it appears, however, that 

 several more years' observation will be necessary to decide which 

 of these is the more accurate. Of y Coronae Australis eight 

 measures were made at Sydney in 1886. The most satisfactory 

 orbit of this binary hitherto published is that computed by Mr. 

 Gore {Monthly Notices, vol. xlvi. p. 104), and the errors of the 

 computed quantities as compared with the observations which 

 have been published since the computations were made are : — 



Epoch. Observed angle. Error. Observed distance. Error. 



1881-72 ... 225-5 ••• + i°'8 ... i'-38 ... - 0-02 

 188362 ... 217-8 ... - 1-3 ... 1-62 ... - 0-33 

 1886-615 ... 200-6 ... - 46 ... 1-45 ... — 033 



The first two of these observations were made at Cincinnati, 

 and published in the Observatory, vol. ix. p. 234, the last at 



Sydney. Mr. Gore's orbit gives 1886-53 ^^ the time of peri- 

 astron passage ; it is very desirable, therefore, that this pair 

 should be repeatedly measured during the next few years in 

 order that the small corrections to the elements which appear to 

 be required may be accurately determined. 



ASTRONOMICAL PHENOMENA FOR THE 

 WEEK 1887 OCTOBER 23-29. 



/'pOR the reckoning of time the civil day, commencing at 

 ^ Greenwich mean midnight, counting the hours on to 24, 



is here employed.) 



At Greenwich on October 23 

 Sun rises, 6h. 39m. ; souths, iih. 44 nn. 26-23, ; sets, i6h. 50m. ; 



decl. on meridian, 11° 24' S. : Sidereal Time at Sunset, 



i8h. 57m. 

 Moon (at First Quarter October 23, i8h.) rises, I3h. 37m. ; souths, 



i8h. im. ; sets, 22h. 28m. ; decl. on meridian, 18° 47' S. 



Planet. 



Rises, 

 h. m. 



Souths, 

 h. m. 



Sets. Decl. on meridian. 



28 ... — 



24 east. 

 Venus at period of greatest morning brilliancy. 



GEOGRAPHICAL NOTES. 

 MM. BoNVALOT, Capus, and Pepin, who have just retunied 

 to France from an extensive journey in Central Asia, are credited 

 with having been the first to cross the Pamir. They may 

 certainly have been the first to take the particular north to 

 south route traversed by them, but the Pamir has been 



a cross^^ 



