256 



NA TURE 



\yan. 14, I i 



The additions to the Zoological Society's Gardens during the 

 past week include a Lesser White-nosed Monkey [CercopithccHs 

 petaurista) from West Africa, presented by Mr. T. Risely 

 Griffith ; a Gray Ichneumon (Herpesies griseus) from India, pre- 

 sented by Capt. J. Cutting ; a Gray Squirrel (Scitirus cinenin) 

 from North America, presented by Mrs. Charles Neck ; a 

 Golden Eagle {Aqiiila chiysados), European, presented by Mr. 

 H. V. Knox ; a Bronze- winged Pigeon [Phaps chalcoptera) from 

 Australia, presented by Mr. Augustus F. Spry ; a Hang- 

 nest (Xanihosomus iclerocephalus) from Venezuela, a Song 

 Thrush (Turdus mnsicus), British, deposited; a White-thighed 

 Co\o\)US {Colobus vfUerosus), a Moustache Monkey (Cercopitlieciis 

 cephiis), a Ludio Monkey {Cercopitheats Indio) from West Africa, 

 received in e.\change. 



OUR ASTRONOMICAL COLUMN 



The Leyden Observatory.— Prof H. G. van de Sande 

 Bakhuyzen has published his Report for the year ending Septem- 

 ber 15, 18S5. The work to which the meridian circle was 

 devoted during the year was the continuation of the observation 

 of a selected list of fairly bright stars situated in the immediate 

 neighbourhood of the Pole. It is expected that this series of 

 observations will be finished oft" during the present winter. 

 With the 7-inch refractor, nine observations of Wolf's comet 

 were made. Between October 18S4 and March 1885, a series 

 of measures have been made with Aiiy's double-image micro- 

 meter attached to this equatorial, for the purpose of determining 

 the systematic errors of the measures of the diameters of Mars 

 and Uranus obtained in fomier years. For this purpose, Prof 

 Bakhuyzen has measured the diameters of artificial disks, formed 

 by circular holes in a copper plate, made so as to resemble, both 

 in size and brightness, the planets themselves. The results of 

 these investigations will be published shortly. The reduction 

 of the meridian observations, 1877-85, is in a forward state, 

 some parts being nearly completed. This work is intrusted to 

 Dr. E. F. van de Sande Bakhuyzen, the First Observer. Some 

 progress has also been made in the reduction of the zone ol)- 

 servations, 1874-76. Prof Bakhuyzen himself has been chiefly 

 occupied with his monograph on the rotation-period of Mars, 

 now published. In March 1885 work was commenced in con- 

 nection with the erection of the new lo^-inch objective, and the 

 instrument is now ready for use. The mounting has been supplied 

 by the Repsolds, and the object-glass by Alvan Clark and Sons. 

 Its performance, so far as it has yet been tested, appears to be 

 remarkably good, and does not compare unfavourably with that 

 of other instruments of similar size. In Prof. Bakhuyzens' 

 hands it will doubtless do good work. 



Fabry's Comet. — Dr. H. Oppenheim gives the following 

 ephemeris for this comet for Berlin midnight : — 



iS36 R.A, Decl. Log A Los; r 



Jan. 17 ... 23 31 4 



19 ... 23 29 58 



21 ... 23 28 58 



23 ... 23 28 3 



25 ... 23 27 14 



-21 53-4 ... 0-2304 ... 0-2025 



22 5-3 



22 i8-2 ... 0-2316 .. 0-1857 



22 32-1 



22 46-9 ... 0-23I9 ... 0-1682 



Brooks's Comet. — The following elements and e^ihemeris 

 have been computed for this comet by Dr. J. Palisa : — 

 T= 1885 Nov. 28-2436 Berlin M.T. 



T = 301 29 50 ) 



n = 262 30 48 \ Mean Eq. 1886-0. 

 i = 42 31 27 \ 

 log q = 0-04091 



Error of the middle place (o - C). 



dK cos 5 = + 47 di = 4"5 



Ephemeris for Berlin Midnight 



Decl. 



Log. 



Bright- 



Jan. 14 ... 21 5 25 ... -1-12 8-6 ... 0-2921 ... 0-1261 ... 0-74 



18 ... 21 20 46 ... 13 48-6 ... 0-2989 ... 0-1377 ... 0-68 



22 ... 21 35 48 ... 15 25-2 ... 0-3064 ... 0-1495 ••■ °'62 



26 ... 21 50 48 ... -)-i6 57-4 ... 0-3146 ... 0-1614 ••• 0'57 



The brightness on December 28 is taken as unity. 



Barnard's Comet. — For Barnard's comet Dr. H. Oppen- 

 heim gives the following ephemeris, also for Berlin midnight : — 



Jan. 17 ... 2 37 45 ... -HI 14-7 



19 ■■ 2 34 22 ... II 38-4 



21 ... 2 31 8 ... 12 25 



23 ... 2 2S 4 ... 12 27-0 



25 ... 2 25 9 ... 12 51-8 ... 0-2213 ... 0-2937 

 GoRio's Nova Orionis. — Dr. Copeland, examining the spec- 

 trum of this object at Lord Crawford's Observatory, Dun Echt, 

 finds distinct evidence of a spectrum of bright bands superposed 

 on a well-marked spectrum of the third type ; these bright bands 

 corresponding to those ordinarily seen in cometary spectra, and 

 obtained in the specrrum of a coal-gas flame. 



ASTRONOMICAL PHENOMENA FOR THE 

 WEEK 1886 JANUARY 17-23 



(For the reckoning of time the civil day, commencing at 

 Greenwich mean midnight, counting the hours on to 24, is here 

 employed. ) 



At Greenwich on January 1 7 

 Sun rises, Sh. om. ; souths, I2h. lom. 24'5s. ; sets, i5h. 21m. ; 

 decl. on meridian, 20° 42' S. : Sidereal Time at Sunset, 

 oh. 9m. 

 Moon (Full on January 20) rises, I3h. S3m. ; souths, 2ih. 44m. ; 

 sets, 5h. 39m.'* ; decl. on meridian, 18° 13' N. 



Planet Rises Souths Sets Decl. on meridian 



h. m. h. m. h. m. . , 



Mercury ... 6 40 ... 10 36 ... 14 32 ... 22 59 S. 

 Venus ... 9 12 ... 14 39 ... 20 6 ... 7 14 S. 

 Mars ... 21 30* ... 4 o ... 10 30 ... 5 9 N. 

 Jupiter ... 22 39* ... 4 38 ... 10 37 ... : 6 S. 

 Saturn ... 14 15 ... 22 25 ... 6 35* ... 22 36 N. 

 * Indicates that the rising is that of the preceding evening and the setting 

 that of the following morning. 



Oecultations of Stars by the Moon 



Corresponding 

 T c. R* T-i- n angles from ver- 



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



inverted image 



17 ... 117 Tauri 6 ... 15 38 



18 ... 130 Tauri 6 ... o 54 



18 ... 26Geminorum... 54 ... 20 37 



20 ... I Cancri 6 ... 2 3 



22 ... 37 .Sextantis ... 6 ... 19 16 



Variab'.e-Star. 



R.A. Decl. 



16 28 ... 33 264 



1 59 ... 124 310 

 21 44 ... 43 271 



2 49 ... 61 33S 

 20 7 ... 33 224 



U Cephei ... 



Algol 



i," Geminorum 



S Cancri 

 5 Librce 



U Corona: ... 

 U Ophiuchi ... 



/3 Lyras 

 1\ Aquilas 

 5 Cephei 



h. 



... o 52-2 ... 81 16 N. ... Jan. iS, o 2 ?« 



,, 22, 23 41 m 



.. 3 0-8 ... 40 31 N. ... ,, 19, 20 o m 



... 6 57-4 ... 20 44 N. ... ,, 18, 5 o VI 



„ 23, 7 30 M 



... 8 37-4 .. 19 27 N. ... ,, 19, 3 23 m 



... 14 54-9 ... 8 4 S. ... ,, 19, 17 20 VI 



,, 22, I II VI 



... 15 13-6 ... 32 4 N. ... ,, 19, 23 6 tn 



... 17 10-8 ... I 20 N. ... ,, 17, 18 41 m 



and at intervals of 20 8 



... 18 45-9 ... 30 14 N. ... Jan. 19, 19 o rn 



... 19 46-7 ... o 43 N. ... ,, 17, o o VI 



... 22 24-9 ... 57 50 N. ... ,, 19, o o M 



,, 22, 19 o ni 



1 



MR. AITKEN ON DEW ^ 

 HE first point referred to in this paper is the source of the 

 vapour that condenses to form dew. A short historical 

 sketch is given of the successive theories from time to time 

 advanced on this point, showing how in early times dew was 

 supposed to descend from the heavens, and then afterwards 

 it was suggested that it rose from the earth, while Dr. 

 Wells, who h.is justly been considered the great master of this 



* Abstract of Paper read before the Royal Society of Edinburgh on 

 December 21, i355. communica-ed by permission of the Council of the 

 Society. 



