September 8, 1892] 



NATURE 



453 



idded another object glass to his equatorial. What he has done 

 lias been to employ a twin cell in which the glasses have been 

 placed ; the whole is then hung on an axis fixed rigidly to the 

 side of the telescope tube so that by a simple rotation each glas;:, 

 whether for photographic or for visual purposes, can be brought* 

 to the centre of the front of the tube. In order to make use of 

 that objective which is not temporarily required for the main in- 

 strument, a tail-piece near the eye-end is also mounted, thus 

 completing another telescope, only without a tube. One great 

 disadvantage of this arrangement would be the difficulty of 

 centring the lenses after each change, but this is not so as we 

 are informed, no difficulty at all being experienced. In As- 

 tronomy and Astro- Physics for August, there is shown a picture 

 of Mars emerging from occultation on July ii, taken without 

 the tube. In the original photograph, which is about ^5^ inch 

 in diameter, the polar caps on the planet are clearly shown 

 together with some of the other markings on the surface. 



Jupiter. — During the next two months the planet Jupiter 

 will be in a very good position for observation. This year he is 

 as much as 5° to 8" north of the equator, being situated now in 

 the constellation of Pisces, just north of the two stars ^ and v. 

 The next opposition occurs on the 12th October. 



Nova Auriga. — In a communication to the Daily Graphic, 

 the Rev. A. Freeman gives the results of some observations of 

 the revived new star in Auriga, made by him on Sunday, August 

 28. Adopting Mr. Stone's values for the magnitudes of the 

 neighbouring stars, the nova would appear to have then been 

 a trifle brighter than mag. io'3, but decidedly fainter than 97. 

 By comparison with the zone star -f 30" 924. the nova was rated 

 at mag. lo'i. As Mr. Espin estimated it to be 9"2 on August 21, 

 it is probable that the star is again waning. 



From the Astrophysical Laboratory at South Kensington we 

 have received the following : — There was no opportunity of 

 -observing the nova here until 1.30 a.m. on Thursday, September 

 I, and it was then too dim to be readily seen with the lo-inch 

 refractor. A photograph of the region was taken with the 

 3i-inch portrait lens, the exposure being thirty minutes, but this 

 failed to show the nova, although clearly showing stars of the 

 loth magnitude. 



Comet Swift, March 6, 1892. — The following is a continua- 

 tion of the ephemeris for Comet Swift, which we take from 

 The Edinburgh Circular, No. 29 : — 



'89^- h.^'^'s. „^"'!' '"g--^- '°g-'-- Br. 



Sept. 8 o 32 27 -f 51 56-5 



9 31 8 51 48-8 



10 29 49 51 407 0-2751 0-4085 0*073 



11 28 30 51 32-1 



12 27 10 51 23-2 



13 25 50 51 13-9 



14 24 30 51 4-1 0-2788 0-4164 0-069 



15 23 II 50 54-0 

 Brightness at time of discovery is the unit of Br. 



The Edinburgh Circular, No. 30, announces the discovery of 

 a comet by Mr. Brooks, at Geneva, U.S., at midnight on the 

 29lh ult. The comet was then in R.A. 6h. 2omin. and de- 

 clination 31° 48' north, its daily motion being +imin. 44sec. 

 and 2' south. The same comet has also been observed at Kiel 

 on the 31st inst. at i2h. 32-2min. ; its place then was found to 

 be R.A. 6h. 5min. 59-isec. North declination 31° 42' 27". 

 Whether this comet is a new one or not cannot of course be said 

 yet for certain, but it is neither Brooks' i886 IV. nor Tempel 

 1867 II. if we can depend on the two search ephemerises we 

 have at hand, for their declinations in both instances should be 

 at this time over 30° south. 



GEOGRAPHICAL NOTES. 

 Montenegro, though one of the smallest, is certainly one of 

 the least known countries in Europe. Dr. K. Hassert, who has 

 already made important journeys in the less known parts of the 

 Balkan peninsula, is this summer travelling through Montenegro, 

 and describes the scenery as in many places of very great beauty. 

 The frontier river Cijevna flows through a steep-sided gorge, the 

 height of the precipices bordering which he estimates as over 

 3000 feet, while in its appearance it rivals the caiions of the 

 Colorado. The traveller in this part of the country runs con- 

 siderable risks from the predatory Albanian tribes. 



The Titnes publishes a telegram from Captain MacDonald of 

 the Mombasa- Victoria-Nyanza, Survey, announcing that the 

 Survey had found a good route for a railway to Sio Bay on the 

 Nyanza, and had returned to Kikuyu on August 8. The 

 Survey work has been carried on rapidly, and, which is more 

 important, without any fighting. 



Railways in tropical Africa may ultimately derive more re- 

 venue from native passengers than might be anticipated. The 

 railway from St. Paul de Loando is being pushed forward to 

 Ambaca, and now nearly reaches Casengo, where there are 

 flourishing coffee plantations under Portuguese management. 

 Until this point is reached the revenue from goods cannot be 

 large, but the natives having speedily got over their distrust of 

 the innovation, now travel freely by rail in large numbers. 



Prof. Pouchet has this summer succeeded in visiting Jan 

 Mayen Island and Spitzbergen in the French gun-boat La 

 Manche. Jan Mayen, on which a landing had not been made 

 for ten years, was visited on July 27, and the vessel proceeded 

 to Spitzbergen, where a fortnight was spent. The west coast 

 was followed up to 78° N., and some excursions made on foot 

 into the interior. Glacier phenomena were studied, and collec- 

 tions of native fauna and of fossils made. The sea was found to 

 be entirely free from ice. 



News has recently been received in Copenhagen of the safety 

 and success of the East Greenland Expedition, which left Denmark 

 in June 1891 under Lieutenant Ryder. The expedition passed 

 the winter on the Greenland coast in Scoresby's Land at a point 

 in 70° 27' N. Important scientific results have been obtained, 

 but the expedition is not yet over. Lieutenant Ryder intending, 

 after a short visit to Iceland, to make an attempt to trace out 

 the hitherto unvisited coast-line between 70° N. and the Arctic 

 circle. 



The first chart on which the American continent appears is 

 being reproduced in facsimile for the approaching Columbus 

 Exhibition in Madrid, The following details are given in a 

 Reuter telegram from Madrid. The work, which is now 

 approaching completion, is being done by Seiior Canovas 

 Vallejo, a nephew of the Spanish Premier, and by Prof. Tray- 

 nor. The original chart, which was traced in the year 1500 by 

 the famous navigator and cartographer Juan de la Cosa, who 

 acted as pilot to Columbus in more than one of his voyages 

 across the Atlantic, has been since carefully preserved in the 

 Naval Museum in Madrid. The chart presents some most 

 interesting features, displaying, as it does, the extent of the 

 j knowledge of the best-informed geographers of the day. On it 

 I are depicted the West Indies and a small portion of South 

 America — namely, the northeastern section lying between the 

 River Amazon and Panama. To this land the general name of 

 I Tierra Firme is given, to mark the contrast between the conti- 

 I nent and the Antilles. Here and there are traces of modern 

 names, such as Venezuela, Maracaibo, and Brazil. The chart 

 even comprises some particulars of the discoveries made in 

 Northern America by Sebastian Cabot in 1497, and such titles 

 as these : — " Sea discovered by the English," " English Cape," 

 " Lizard," and " St. George." La Cosa has also clearly 

 depicted Cuba as an island, whereas Columbus died in the 

 belief that it was a continent, and it was not until eight years 

 later that the correctness of La Cosa's chart was in this respect 

 finally established. 



AMERICAN ASSOCIATION FOR THE 

 ADVANCEMENT OF SCIENCE. 



Rochester Meeting, 



'X'HE forty-first annual meeting of the American Association 

 -*■ for the Advancement of Science was held at Rochester, 

 New York, August 17-23, Prof. Joseph LeConte, of California, 

 the well-known geologist, presiding. 



Rochester is one of the most beautiful of American cities, 

 being laid out quite on the rus in urbe principle, so that each 

 residence is generally surrounded by grounds, instead of being 

 built in a solid block. It is pre-eminently a city of freeholders, 

 as appears by the fact that a recent census showed more land- 

 owners than voters in the city. It is moreover situated in the 

 beautiful and picturesque region of western New York, within 

 a veiy short distance from numerous glacial lakes, as well as the 



NO. I 193. VOL. 46] 



