374 



NA TURE 



[August 20, 1896 



just published will make Fellows of the Society proud of their 

 Fellowship, and will arouse a spirit of emulation among chemists 

 in many parts of the world. 



Stuiients of meteorology will be glad to know that three 

 important essays on Australian weather have, by the generosity 

 of the Hon. Ralph Abercromby, been brought together and 

 published in book form. The first essay, on " Moving Anti- 

 cyclones in the Southern Hemisphere," by Mr. H. C. Russell, 

 F. R.S., was originally read before the Royal Meteorological 

 Society, and published in the Society's Journal. The leading 

 fact brought out in this paper is that Australian weather south of 

 lat. 20^ S. is the product of a series of rapidly moving 

 anticyclones, which follow one another with remarkable 

 regularity, and are the great controlling force in determining 

 local weather. These anticyclones travel eastward at the 

 average rate of four hundred miles per day, and they do so with 

 such regularity that the prospect is held out of weather predic- 

 tions being made some weeks in advance, or even for longer 

 periods. The second essay in the volume is the one, by Mr. H. 

 A. Hunt, on " Southerly Bursters," which won the prize offered 

 by the Hon. Ralph .\bercromby. This essay was noted in 

 Nature in January 1895 (^'°1- ''• P- 230). The third essay, 

 which is also by Mr. Hunt, has for its subject " Types of 

 Australian Weather." This discussion throws much new light 

 upon the source of the greater part of Australian rain, and at the 

 same time forms an important contribution to the study of 

 weather in the southern hemisphere generally. The volume 

 containing these essays is published by Mr. F. W. White, 

 Sydney. 



The additions to the Zoological Society's Gardens during the 

 past week include four Malabar Squirrels (Sciurtts tiiaxiiiius) 

 from Southern India, presented by Mr. W. J. Stillman ; two 

 Sclater's Curassows (C;-ax sclateri) from Minas Geraes (Brazil), 

 presented by Mr. E. Sumead ; a Temminck's Stint (Triiiga 

 ieinniincki), British, presented by Mr. E. C. Sprawson ; a 

 Golden Eagle [Acjuila ckrysielus) from Spain, presented by Mr. 

 F. Leathly Holt ; three Common Blue-birds {Sialia wilsoiiii) 

 from North America, presented by Mr. A. T. Binny ; two Stone 

 Curlews (.^uiiiiieiiiKS scolopax], British, presented by Mr. W. 

 J. Kidman ; two Common Blue-birds {Sialia wilsonit) from 

 North America, i)resented by Mr. Percy Cockshut ; three 

 Common .Adders i I'ifera hcnis), British, presented by Mr. A. 

 Old ; three Peruvian Snakes (Tac/iymeiiis peruviana) from 

 Peru, presented by Mr. A. H. Jamrach ; a White-browed 

 Amazon {Chrysotis alltifrons) from Honduras, purchased ; a 

 Wapiti Deer {Cei-ous canadensis, 9 ), bred in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



Lunar Photoi;rai'HS. — Prof. Weinek, whose artistic skill 

 in the enlargement of lunar photographs cannot but be admired, 

 and who has co operated with the staff of the Lick Observatory 

 in reproducing from their negatives the more interesting features 

 of the moon, has recently made a further contribution to the 

 Vienna Academy of fifteen enlargements of certain details on 

 the lunar surface, as .seen at the third quarter. Also, Aristarchus 

 and Herodotus have been drawn with the shadows thrown on 

 the western side as a companion picture to an earlier enlarge- 

 ment in which the shadows are thrown to the east. Dr. Weinek 

 now takes the opportunity of calling attention to the fact that, 

 in many instances, his drawings, indicating the existence of 

 minute detail, have been confirmed by Dr. (jaudibert from 

 optical examination of the moon itself. This remark refers to 

 drawings from original negatives taken both at the Lick and 

 Paris Observatories. The differences between the photographic 

 reproductions and Schmidt's map are admitted, and according 

 to the description furnished by Dr. Gaudibert, it is a little 

 difficult to explain some of the omissions from this well-known 

 authority. 



NO. 1399, VOL. 54] 



Distribution of Binary-Star Orbiis.— Miss Everett 

 gives in Monthly Notices, ]wa& 1896, pp. 462-466, the residts 

 of an attempt to discover if the planes of the orbits of binary 

 stars have any relation to the plane of the Milky Way. To do 

 this, the most accurate values of the elements of fifty-five orbits 

 were taken, and from these the galactic longitudes and latitudes 

 of the poles of the orbits were calculated and tabulated. Gould's 

 value of the position of the galactic northern pole was assumed, 

 viz. R.A. I2h. 42m. 4s. (190" 31'), Deck -f27' 16' (Epoch 1890). 

 This gives the obliquity of the central line of the Galaxy as 62° 

 7', and the position of the ascending node is at R.A. = l8h. 42m. 

 (280° 31'), from which the galactic longitudes are reckoned. On 

 examining the tables, it appears that equal surface zones contain 

 nearly similar numbers of orbit poles, and it is concluded that 

 there is no decided tendency on the part of the poles of the 

 orbits to favour any special region of the celestial sphere, and 

 hence that the planes of the orbits cannot be regarded as having 

 any definite relation to the mean plane of the Galaxy. 



Comet 1890 VH. — The orbit of this comet, which was first 

 seen by Dr. Spitaler of Vienna, while searching for one recently 

 discovered by M. Zona of Palermo, has been submitted to a 

 thorough examination by the original discoverer, with the result 

 that the period of six and half years has been confirmed. 

 Consequently, its return to perihelion may be looked for next 

 spring, and Dr. Spitaler has prepared ephemerides to facilitate 

 its search. The most favourable time for observation will be 

 next month, when the comet will be in opposition, but the 

 theoretical brilliancy will be only about one-fourth that possessed 

 at the time of discovery in 1890. The considerable southern 

 declination of the comet will render its detection in these latitudes 

 still more difficult. The next return in 1903 will be still more 

 unfavourable, and though 1909 may offer good chances for 

 observation, the error of position will be larger. Dr. Spitaler 

 thinks that the ephemeris he has preparetl for this return is 

 trustworthy to about five minutes of R.A. and forty minutes of 

 Declination. 



Photography of Soijvr Corona.^ — Count de la Baume 

 Pluvinel has recently discussed the conditions necessary for suc- 

 cessfully obtaining photographs of the corona [Bulletin de la .'tor. 

 .4st. de France, July 1896). The difficulty of the problem lies in 

 the varying intensity of the several parts of the corona, the 

 delicate details being lost in long exposures on the inner region, 

 while in short exposures the outer corona is almost absent. During 

 the eclipse of April 1893, the author attempted to determine the 

 best value of the "photographic action " necessary for depictim; 

 the coronal structure without allowing the light from the surround- 

 ing sky to produce any deteriorating effect. The term " photo- 

 graphic action " is defined as being proportional to the product 

 of the intensity of the image and the duration of exposure, and 

 is accepted as being constant within certain limits. For this 

 purpose he employed a compound camera having nine object- 

 glasses, with apertures varying from 5 mm. to 155 mm., and 

 average focal length of I '5 metres. The time of exposure for 

 all was 230 sees., and consequently the photogiaphic action had 

 values varying from 0^24 to 250. From the various photographs 

 obtained he concluded that, for that particular climate (Joal) a 

 photographic action of about 4 was best. From other photo- 

 graphs taken in Brazil, he recommends a value of 10 to be used 

 in future eclipses, this value to be diminished or augmented as 

 the .sky light is greater or less than that in 1893. The above 

 law of photographic action ceases to hold beyond certain limits ; 

 as the intensity of the light decreases, the time of exposure 

 must be enormously increased, and this fact has led the author 

 to suggest a method of photographing the corona without an 

 eclipse. It involves the design of a telescope with such a ratio 

 between aperture and focal length that the sky illumination will 

 be too feeble to affect the plate, while the slightly greater 

 intensity of the corona will allow of its being photographed with 

 a long exposure. 



NANSEN'S POLAR EXPEDITION. 

 ■pvR. NANSEN arrived at Vardo, Norway, on Thursday, 

 August 13, after an absence of three years. A Reuter 

 telegram says that he left the Frain with a companion on March 

 14, 1895, in lat. 84° N., in order to push further north 

 into the Polar Sea than the Fram could penetr.ate. The 

 expedition accomplished its object in traversing the Polar So i 

 to a point north of the New Siberia islands. The most northerl) 



