February 23, 1893] 



NATURE 



399 



sanouinea and Sigalion boa, and of the Nudibranch Anciila cris' 

 tata. In addition to the forms mentioned last week, the 

 townettings have contained the Siphonophore Muggicea atlan- 

 tica, the Anthomedusa Margellium {Lhzia) octopunctatum, and 

 several ephyrae of Aurelia, together with numbers of Teleostean 

 ova, Prosobranch and Opisthobranch veligers, larval Lamelli- 

 branchs and Cyphonauies ■Xa.rvx. The Polychsete Cirratulus 

 <:trmi us &nd Gdsiropod Litiorina littoralis are also breeding. 



The additions to the Zoological Society's Gardens during the 

 past week include a Vervet Monkey {Cercopithecus lalandii) 

 from South Africa, presented by Mr. Walter Neall ; two Red 

 and Yellow Macaws {Ara chloroptera) from South America, 

 presented by Mr. Henry Goschen ; a Herring Gull (Larus 

 argentatus) European, presented by Mr. W. R. Galbraith ; a 

 Bar-breasted Finch {Munia nisoria) from Java, presented by 

 Mr. Sydney D. Birch ; two Whooper Swans [Cygnus musicus) 

 European, purchased ; a Vulpine Phalanger '{Phalangista vul- 

 pina), three Barbary Mice (Mus barbarus) born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 

 C0.MET Brooks (November 19, 1892). — The following 

 ephemeris for Comet Brooks is taken from Astronomische Nach- 

 richten, No. 3142 : — 



Comet Holmes (1892 IH.).— Several communications with 

 respect to the late appearances of this comet are inserted in the 

 Comet Notes of Astronomy and Astrophysics for February, 

 among which will be found one by Prof. E. Barnard. Observing 

 with a 12-inch on the night of January 16, at 8h. lom., he 

 found that an estimation of the comet's diameter gave 30", while 

 a setting of the wires indicated 29" 4. While under observation 

 ^^ the comet seemed to be perceptibly brightening," and further 

 measurements at 9h. 45m. gave a diameter of 32"*4. At this 

 time he says; "The nucleus had developed clearly, and was 

 very noticeable as a small, ill-defined star." With the 36-inch, 

 which he was able to use later, he made the following measures, 

 which we reproduce here, as they are quite unique in showing 

 the increase in diameter of a comet due evidently to some 

 external impact : — 



Diameter. 



Standard Pacific time, 

 h. m. 

 10 29 

 10 30 

 10 31 

 10 42 



10 43 

 ID 45 



11 13 

 II 15 



43 4 



44 '9 

 436 

 47-8 

 47 9 

 46 o 

 47 '3 

 46-1 



In cpncluding his remarks he says : " This is certainly the 

 most remarkable comet I have ever seen, taking everything into 

 consideration." 



The following is the ephemeris for this week : — 



1893. 



Greenwich, Midnight. 



R.A. (app ) Decl. (app.] 



Feb. 23 ... 2 19 4-4 



24 ... 20 44'6 



25 ... 22 25-5 



26 ... 24 6'4 



27 ... 25 48-0 



28 ... 27 29-6 

 March i ... 29 11 '9 



2 ... 2 30 54-3 



+ 34 31 7 

 7,1 36 

 36 9 

 38 42 

 41 18 

 43 54 

 46 34 

 34 49 13 



Solar (Observations at Rome.— In the Memorie Degli 

 Spettroscopisti Italidni for January, Prof. Tacchini communi- 



NO. 1217, VOL. 47] 



cates the observations made at the Royal College with respect 

 to the various phenomena observed at the solar surface during 

 the third trimestre of 1892. Dealing first with the prominences 

 the total number for each of the months are respectively for 

 north latitudes, 182, 129, 120, total 431 ; and for south latitudes 

 141, 167, 185, the total number here amounting to 493. The 

 balance here is in favour of the southern hemisphere for greater 

 frequency, but a curious fact may here be remarked, and that is 

 that the maxima for the north and south latitudes occur in the 

 months of July and September respectively, each exceeding con- 

 siderably the number of prominences recorded for the same 

 month in the opposite hemisphere. 



The greatest frequencies occurred in latitudes (-f-6o° + 70°) 

 and ( -50° -60°). The groups of spots seem to have pre- 

 dominated slightly in the southern latitudes, the record show- 

 ing 49 against 41 ; at the equator as many as 13 for zone 

 (o°-t-io°) were seen, the zone (0° — 10°) showing only 4 ; the 

 relative frequency occurred here in the same zones in both 

 hemispheres (±io''±20°). 



With reference to eruptions, the month of July contains the 

 only records, six for the northern, and three for the southern 

 hemisphere, four of these taking place in zone (-f- io'' + 20°). 



Prof. Tacchini also has a note on the great prominence of 

 November 16 last, in which he describes in detail the numerous 

 observations which he was fortunate to procure. Although one 

 can gather a good idea of the rapidity of the ascent from the 

 table, the figures which accompany it show in a striking manner 

 the great changes of shape that was such a conspicuous feature in 

 its ascent. At 9h. oip. on the i6th the height was only I3i"'8, 

 but at ih. it had reached 319" '2, and at ih. 35m., 534"'3, this 

 being its maximum height. It is interesting to notice the numbers 

 showing the increase of altitude in one minute of time. 



For instance, at iih. 55m. the increase of altitude per minute 

 was o"*56, at ih. 4m. it was 6" 75, decreasing from this value 

 to 4" "34 at ih. 27m. At ih. 32m. the velocity of ascent was 

 increased, the value amounting to 9"'72, but at ih. 34m. the 

 increase of altitude reached its maximum, 20" "So, showing the 

 ascent per minute. 



The Star Catalogue of the " Astronomische Gessel- 

 SCHAFT," — The Harvard College Observatory has now com- 

 pleted the task of cataloguing the zone of stars undertaken in 

 connection with the great catalogue of the Astronomische Gessel- 

 schaft. The stars included number 8627, and lie between 

 49° 50' and 55^ 10' north declination, and the positions are re- 

 duced to the epoch 1875. Most of the observations were made 

 by Prof. Rogers during the years 1870-1884, and the reductions 

 have throughout been in his charge. The publication appears 

 simultaneously as vol. xv. part ii. of the Annals of the Harvard 

 Observatory, and as one of the volumes of the Gesselschaft. All 

 concerned are to be congratulated on the completion of the zone, 

 which involved over twenty-six thousand observations and an 

 immense amount of calculation. 



Nova Aurig^e. — Mr. Fowler draws attention to the fact that 

 the nova is still as bright as ninth magnitude, and therefore easily 

 visible in comparatively small telescopes. Its spectrum seems to 

 consist of the two bright nebula lines near wave-lengths 5006 

 and 4956. The latter is only slightly fainter than that at 5006. 



Parallax of j3 Cygni. — Mr. Harold Jacoby, whose work 

 on the reduction of the Rutherford photographic measures of 

 the stars about 3 Cygni we have previously referred to, suggests 

 in Astronomical Journal, No. 287, that the discrepancies in 

 the results can be explained on the hypothesis of a parallax of 

 ^ Cygni amounting nearly to a whole second of arc. To in- 

 vestigate this he has chosen five pairs of comparison stars, from 

 which he has computed the parallax from each pair separately 

 by " usifig the difference of the distances of the two comparison 

 stars from ^ as the quantity from whose variation the parallax 

 should appear ; " in this way he has obtained the weighted mean 

 for the parallax to be ->- o"'97, a value which, if endorsed by 

 further observations will show us that of all stars & Cygni is one 

 of our nearest neighbours. 



GEOGRAPHICAL NOTES. 



Mr. G. B. Grundy, of Brasenose College, the student in 



geography appointed jointly by the University of Oxford and 



the Royal Geographical Society, has made a careful survey of 



the battlefield and site of the town of Plaloea and of Leuctra, 



