May 19, 1887] 



NATURE 



65 



minished that the Kirghizes already ford the strait which con- 

 bets it with the lake. None of the rivers given on our maps 

 m flowing into the Ala-kul Gulf and Lake Balkhash from the 

 I Buth-west were found by M. Krasnoff. They have all dried up. 



\ I The additions to the Zoological Society's Gardens during the 



'3^ jast week include an Alexandrine Parrakeet {Palaornis alex- 



] ttdri) from India, presented by Miss Ada Marshall ; two 



\ hinese Geese {Amer cygnoides) from China, presented by Miss 



, loare ; four Midwife Toads {Alytes obsietricans). South 



! [aropean, purchased ; a Blue-cheeked Parrakeet {Flatycercus 



\yanogenys) from North Australia ; a Pied Crow Shrike {Strepera 



\raculitta) from Australia ; a Sun Bittern {Eurypyga helias) 



I om South America, received in exchange ; a Blood-breasted 



I'igeon {P/ilogccnas cruentata) ; two Dwarf Chameleons (CV/a- 



\i<rleon pumilus) bred in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



MiCROMETRic Measures of Jupiter and Saturn. — In 

 he recently- published " Observations," made at the Hong 

 Cong Observatory during 1886, Dr. Doberck gives some mea- 

 ures of [upiter and Saturn made with the 6-inch Lee equatorial 

 jiow at Hong Kong. The measures of Jupiter, extending from 

 IVugust 29, 1879, to April 7, 1886, include the position-angle of 

 Ihe polar axis, the apparent equatorial and polar diameters, the 

 Weadth of the equatorial belts and of the red spot, and the 

 ength of the latter when on the central meridian. Dr. Doberck 

 concludes that the equatorial and polar diameters at the mean 

 iistance of Jupiter are 38" '207 and 35" '942 respectively, and 

 hat the equatorial semi-diameter at the mean distance of the 

 ;arth from the sun is 99" '39. The measures of Saturn extend 

 rom January 3, 1879, to April 5, 1886, and include the position- 

 mgle of the polar axis, the external diameter of the ring, the 

 liameter of Cassini's division, the internal diameter of the ring, 

 ind the equatorial and polar diameters of the planet. The 

 deduced dimensions at the mean distance of Saturn are : — 

 l^^xtemal diameter of ring 40" '28, diameter of Cassini's division 

 54" '42, internal diameter 26" '82, equatorial diameter of Saturn 

 1 7" '22, and polar diameter 16" •53. The equatorial semi- 

 liameter at the mean distance of the earth from the sun is 

 :i2"-n. 



Present Appearance of Saturn's Ring. — M. Sluyvaert, 

 tVssistant-Astronomer at the Royal Observatory, Brussels, has 

 ecently presented a couple of drawings of Saturn to the Royal 

 IJelgian Academy. Tliese were made on February 8 and 15 in 

 he present year, and show the Cassinian division as encroaching 

 m the outer ring. A, in a remarkable series of shaded indenta- 

 ions. Ring B is nearly broken up into a series of bright white 

 ;pots by a number of dusky indentations on its inner border of a 

 iimilar shape, and the dusky ring, C, likewise shows two dark 

 lotches on the inner side of the following ansa. Struve's division 

 between B and C was also seen, and appeared on February 8 to 

 e formed by a succession of dark gray spots. These observations 

 ire largely supported by those of Dr. Terby and Mr. Elger, 

 published in the Observatory for March and April. Mr. Elger 

 )bserved three or four "large re-entering angles like the teeth 

 )f a saw" on the inner margin of the dusky ring. This was on 

 he preceding ansa, and not the following, as in M. Stuyvaert's 

 )bservations, but the rotation of the ring would account for the 

 ;hange. Mr. Elger also noticed on February 25 that the pre- 

 ;eding ansa of the dusky ring was unequally black, certain parts 

 )f its surface appearing quite black. These black spots were 

 ilso noticed and drawn by Dr. Terby, who likewise remarked 

 he unusual distinctness and breadth of Struve's division. It 

 vould appear, therefore, from these and other recent observations 

 hat the matter composing the ring system is at present much less 

 ymmetrically and evenly distributed than usual. Irregularities 

 n the inner borders of the various rings, such as the above 

 (bservers describe, have indeed been observed before, Trouvelot, 

 or example, having remarked notches in King A, and Jacob 

 imilar indentations in the dusky ring, but they are not ordinarily 

 een. 



The Red Spot upon Jupiter. — From some recent observa- 

 ions of this object published by Mr. Stanley Williams in the May 

 lumber of the Observatory, it appears that the ephemeris given 



by Mr. Marth in the Monthly Notices for November 1886, is 

 about a quarter of an hour too late. The red spot may therefore 

 be expected to be on the central meridian at about the following 

 times : — 



h. m. 



May 24. ..21 33 

 ,, 26... 23 II 

 ,, 29... o 49 

 „ 31. ..22 19 



June 2. ..23 57 

 ,, 5. ..21 27 



June 7. ..23 6 

 ,, 10. ..20 35 

 ,, 12. ..22 14 

 „ 14. .23 53 



» IS-I9 43 

 ,, 17. ..21 22 



h. m. 

 June 19. ..23 o 

 ,, 22. ..20 30 

 ,, 24... 22 8 

 „ 26... 23 46 

 „ 27. ..19 38 

 ,, 29. ..21 16 



The above times are expressed in Greenwich civil time, and 

 are reckoned from midnight to midnight. 



Discovery of a New Comet. — A new comet was dis- 

 covered on May 12, by Mr. E. E. Barnard, Nashville, Tennessee, 

 U.S.A. Place, May 12, i6h. S7m., R.A. I5h. lom. 58s., Decl. 

 31° 25' S. The comet was only faint. 



ASTRONOMICAL PHENOMENA FOR THE 

 WEEK 1887 MAY 22-28. 



/"pOR the reckoning of time the civil day, commenciDg at 

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



is here employed. ) 



At Greenwich on May 22. 

 Sun rises, 4h. im. ; souths, iih. 56m. z^'6%. ; sets, I9h, 52m. ; 

 decl. on meridian, 20° 23' N. : Sidereal Time at Sunset, 

 iih. 52m. 

 Moon (New" on May 22) rises, 4h. i8m. ; souths, iih. 38m.; 

 sets, I9h. 9m. ; decl. on meridian, 14° 17' N. 

 Planet. Rises. Souths. Sets. Decl. on meridian, 



h. m. h. m. h. m. « / 



Mercury ... 3 47 ... 11 31 ... 19 15 ... i8 38 N. 



Venus 6 17 ... 1447 ... 23 17 ... 25 14 N. 



Mars 3 43 ... II 29 ... 19 15 ... 18 56 N. 



Jupiter 16 26 ... 21 43 ... 3 o* ... 9 14 S. 



Saturn 7 16 ... 15 23 ... 23 30 ... 22 8 N. 



* Indicates that the setting is that of the following mornine. 

 May h. 



26 ... 8 ... Venus in conjunction with and 5° 18' north 

 of the Moon. 



26 ... 17 ... Saturn in conjunction with and 2° 45' north 



of the Moon. 



27 ... 14 ... Mercury in superior conjunction with the Sun. 



Variable Stars. 

 Star. R.A. Decl. 



h. m. , / h. m. 



U Cephei o 52*3 ... 81 16 N. ... May 24, 2 18 m 



U Canis Minoris... 7 35 '2 ... 8 39 N. ... ,, 22, • m 



5 Librae 14 54-9 ... 8 4 S. ... ,, 28, 2 44 m 



U Ophiuchi 17 io'8 ... i 20 N. ... ,, 25, i 48 m 



and at intervals of 20 8 



W Sagittarii ... 17 57-8 ... 29 35 S. ... May 28, 21 o M 



7/ Aquil« 19 467 ... o 43 N. ... ,, 27, 3 o m 



R Sagittae 20 8'9 ... i6 23 N. ... ,, 28, m 



R Vulpeculse ... 20 59*4 ... 23 22 N. ... ,, 22, m 



5 Cephei 22 25-0 ... 57 50 N. ... ,, 26, 3 o m 



M signifies maximum ; tit minimum. 

 Meteor-Showers. 



R.A. Decl. 



Near Draconis 



7 Cygni ... 



From Lacerta ... 



280 

 301 

 329 



54 N. 

 37 N. 

 48 N. 



GEOGRAPHICAL NOTES. 



The new Erganzungsheft (No. 86) of Petermann's MUteil- 

 ungen contains a monograph of great importance in scientific 

 geography by Dr. Rudolf Credner, Professor of Geography at 

 Greifswald, on "Die Reliktenseen," which he defines broadly 

 so as to include all lakes of marine origin, whether they do or 

 do not now contain remains of marine fauna. The author con- 

 siders such lakes of so great importance in connexion with the 

 evolution of the earth, that he thinks it the duty of physical 

 geography to critically examine ail data concerning lakes which 

 may have a claim to be regarded as of marine origin, and 



