2 5 8 



NA TURE 



\_July 12, 1888 



clusters — that the Lick photographic telescope will find its 

 chief application and demonstrate its immense superiority. One 

 ■of the first works to be done is to photograph the vicinity of all 

 the brighter stars, for the discovery of fainter companions, and 

 for the permanent record of their surroundings. A certain number 

 of stars will be selected and photographed at regular intervals 

 throughout the year. Measures made upon these plates will give 

 the data by which the distances of these stars from the earth can 

 be determined. Similar measures upon photographs of star 

 •clusters may serve to give us a clue to the laws which govern the 

 internal structure of these wonderful objects. A continuous series 

 of photographs of the brighter parts of one of the brighter comets 

 will certainly throwa flood of much needed light upon the process 

 of their development." 



The additions to the Zoological Society's Gardens during the 

 past week include a White-thighed Colobus (Colobus vcllerosus 

 3 ), a Campbell's Monkey {Ccrcopithecus campbelli V ), a White- 

 Collared Mangabey (Cercocebus collarii), a Bosnian's Potto 

 (Perodicticus potto), a Marabou Stork (Leptoptilus crumeniferus), 

 a Black Sternothere (Slemothcerus nigcr) from West Africa, pre- 

 sented by Mr. H. H.Johnston, F.Z.S. ; two Black-Bellied Sand 

 Grouse (Pterocles arenarius) from North Africa, presented by Sir 

 Kirby Green, R. C.M.G. ; an Eyed Lizard (Licerta ocellata), 

 European, presented by Mr. J. Hopson ; a Patas Monkey (Cer- 

 topithectis patas ), two West African Love Birds (Agapornis 

 pullaria) from West Africa, a Cormorant {Phalacrocorax carbo), 

 British, three Scarlet Ibises (Eudocimus ruber) from South 

 America, five Common Chameleons {Chamcele n vulgaris) from 

 North Africa, deposited ; a Chipping Squirrel (Tamias striatus) 

 "from North America, five Lesser Pintailed Sand Grouse (P.cro les 

 .■exustus 1 6 , 3 9 ) from Abyssinia, two Modest Grass Finches 

 (Amadina modesta) from Australia, purchased ; a Moor Monkey 

 (Semnopithccus maurus 6 ) from Java, received in exchange ; a 

 Spotted Tinamon (Nothura maculosa), two Cambayan Turtle 

 Doves {Turtur senegalensis), three Chiloe Widgeon (Maieca 

 chilosnsis), three Slender Ducks {Anas gibber/frons), two Aus- 

 tralian Wild Ducks (Anas supcrciliosa), three Mandarin Ducks 

 (sEx galericulata), eleven Chilian Pintails (Dafila spinicanda) 

 bred in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



The Markings on Maks. — M. Perrotin, in a more recent 

 communication to the Paris Academy of Sciences, states that 

 the district of Libya, the disappearance of which he had recorded 

 a week or two earlier (Nature, vol. xxxviii. p. 185), 

 has undergone a further change, the "sea" which had so 

 recently covered it having retreated again for the most part, so 

 that the present appearance of the district is intermediate be- 

 tween that which it recently presented and that under which it 

 was seen in 1886. Of the canals M. Perrotin has noticed four, 

 three of which are double, which, starting from the "seas" of 

 the southern hemisphere near the equator, and following a 

 nearly meridional course, extend right up to the north polar ice 

 cap, being traceable across the "seas" which immediately 

 surround the latter. No other observer as yet seems to have 

 traced these canals for such a distance, and across "seas" as 

 well as continents. This observation renders their true character 

 more puzzling than ever, and seems effectually to dispose both of 

 M. Fizeau's just published theory, which explains them by the 

 analogy of the rifts in terrestrial glaciers, Mars being assumed to 

 be in a glacial condition, and of that of Mr. Proctor, who 

 -ascribes them to the varying appearances of the Martial rivers 

 when clearly seen or partly veiled by local mists. More detailed 

 observations of these strange markings are needed, and it 

 is to be much desired that as many as possible of actual drawings 

 made at the telescope should be published. It is possible that 

 the comparison of sketches made with different observers and 

 -with different apertures, would throw much light on the subject ; 

 if, for instance, the appearances were partly optical and due to 

 :some effect of diffraction, it would soon become apparent. 



Comet 1888a, Sawerthal. — The remarkable change in 

 brightness which this object displayed about May 20 (Nature, 

 vol. xxxviii. p. 114) seems to have been well observed, and 

 there is a general agreement that the increase in brightness 

 amounted to 24 or 3 magnitudes. At Dorpat Herr Blumbach 

 estimated the comet as 9-10 on May 19, and as 7-8 on May 22. 

 Dr. Franz, at Konigsberg, considered the increase as amount- 

 ing to 3^ magnitudes, estimating the brightness as 5 8 on May 

 21, whilst Dr. Kammeraoann, at Geneva, on May 25, reckoned 

 the comet as between the 5th and 6th mags., and the increase 

 as having been between 2 and 3. Father Fenyi, of the Kalocsa 

 Observatory, finds the change of magnitude about the same, but 

 estimates the absolute brightness differently ; the recorded 

 magnitudes being: JVIay 20, 9-3 ; May 21, 78; May 22, 68; 

 and May 23, 6 '8. Father Fenyi also supplies {Astr. Nach., 

 No. 2844) a series of sketches of the comet, showing the changes 

 of shape which have accompanied the changes of brightness, 

 and especially the development about May 28 of a sort of wing 

 on either side of the head. These wings appear, however, to 

 have been seen earlier at other observatories, thus Herr 

 Kortazzi, at Nicolaiew, observed them on May 24, and Herr 

 Wutschichowski gives a beautiful drawing of them under date 

 May 25 (Astr. Nach., No. 2845). The comet does not appear 

 to have been satisfactorily observed with the spectroscope during 

 this period of unusual brilliancy. The outburst was soon over, 

 and the comet speedily returned to it- former faintness. 



The following ephemeris (Astr. Nach., No. 2838) is in con- 

 tinuation of that given in Nature, vol. xxxviii. p. 186. 



1888. R A. Decl. L^g r. Log .A. Bright- 



h. m. s. o / ness. 



July 13 .. 1 7 18 ... 50 32 8 N. ... 03352 ... 0-3306 ... 0029 



15... 1 742 ... 5055-4 



17... 1 7 56 ... 51 17-2 



19... 1 8 2 ... 51 38-4 



21... 1 757 ... 51 58-8 



23... 1 743 ... 52 18-5 



25... 1 7 19 ... 52374 



27... 1 645 ... 52 55-4 



29... 1 6 o ... 53 126 



31... 1 5 6 ... 53 28-9 



Aug. 2... 1 4 1 ... 53 44-2 N. ... 0-3857 ... 0-3405 ... 0-022 



... 0*3459 ... 0-3331 ... o 028 

 ... 0-3563 ... 0-3353 ••• °'° 2 ° 

 ... 0-3664 ... 03372 ... o 025 

 ... 0-3762 ... 03389 ... 0023 



The brightness on February 18 is taken as unity. 



ASTRONOMICAL PHENOMENA FOR THE 



WEEK 1888 JULY 15-21. 

 /T70R the reckoning of time the civil day, commencing at 

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



is here employed. ) 



At Greenwich on July 15 

 Sun rises, 4h. 3m. ; souths, I2n. 5m. 44-23.; sets, 2oh. 8m. : 

 right asc. on meridian, 7h. 40-801. ; decl. 21° 26' N. 

 Sidereal Time at Sunset, 15(1. 44m. 

 Moon (at First Quarter July 16, I2h.) rises, nh. 7m. ; souths, 

 I7h. 21m. ; sets, 23(1. 22m.: right asc. on meridian, 

 I2h. 566m. ; decl. o" 35' S. 



Right asc. and declination 

 Planet. Rises. Souths. Sets. on meridian. 



h. m. h. m. h. m. h. m. „ , 



Mercury.. 3 44 ... 1 1 24 ..19 4 ... 6 58-6 ... 18 o N. 

 Venus ... 4 4 ... 12 11 ... 20 18 ... 7 45-9 ... 22 9 N. 

 Mars ... 12 56 ... 18 2 ... 23 8 ... 13 38-3 ... 11 15 S. 

 Jupiter ... 15 38 ... 20 2 ... o 26*... 15 38-0 ... 18 36 S. 

 Saturn ... 5 19 ... 13 6 ... 20 53 ... 8 4i - 8 ... 18 56 N. 

 Uranus... 11 34 ... 17 14 ... 22 54 ... 12 50-3 ... 4 42 S. 

 Neptune., o 39 ... 8 25 ... 16 11 ... 3 59-5 ..18 53 N. 

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



Comet Satverthal. 



Right Ascension. Declination. 



July. h. h. m. „ / 



15 ... o ... i 7-5 ... 50 45 N. 

 19 ... o ... 1 80 ... 51 28 



Occultations of Stars by the Moon (visible at Greenwich). 



Corresponding 



angles from ver- 



July. Star. Mag. Disap. Reap. tex to right for 



inverted image, 

 h. m. h. m. 00 



17 ... £' Libra 6 ... 19 22 ... 19 40 ... 145 176 



18 ... Libra: 4^ ... 21 2 ... 21 23 ... 8 359 



19 .. 49 Libra: 54 ••• o 20 near approach 202 — 



19 ... B.A.C. 5700 ... 64 ... 22 26 .. 23 14 ... 142 232 



