566 



NA rURE 



[_April 15, 18S6 



bition is to illustrate the history and development of photography, 

 and to show the numerous and important applications of the art 

 to science, art, and industry. All objects selected for exhibition 

 will be chosen with the view of promoting the educational value 

 of the collection. The elements of competition and trade will 

 not enter into the Exhibition, nor will there be any prize offered 

 to exhibitors. Portraits will be shown only in so far as they may 

 serve to illustrate the various methods of portrait photography, 

 or special features of size, treatment, &c. Landscapes may be 

 accepted on account of the interest of the subject, as well as for 

 technical excellence. Reproductions of art objects will be 

 received both as illustrations of processes and for the artistic 

 interest and importance they possess. Communications respect- 

 ing the business of the Exhibition should be addressed to the 

 Secretary of the Museum and Galleries Committee, Town 

 Council, Glasgow. 



Mr. George R. Rogerson, an old pupil of the College, has 

 presented his valuable astronomical observatory to the Council 

 of Liverpool College. The instruments include an equatorially- 

 mounted refracting telescope, a spectroscope with ten prisms, a 

 micrometer, and also an astronomical library. 



An important essay on micro-chemical reactions has just been 

 published in Brussels by MM. Klement and Renard. Availing 

 themselves of the published researches of Boricky, Behrens, 

 Streng, Lehmaun, Haushofer, and others, combined with 

 the results of their own extensive researches, the authors have 

 produced the most complete account of the subject which has 

 yet appeared. They describe the methods of research and the 

 reactions, simple and characteristic, by which compounds of more 

 than fifty elementary bodies may be identified in minute crystals 

 recognisable under the microscope. They also give a brief 

 description of the processes of isolation and identification appli- 

 cable to such compounds as the mineral constituents of rocks. 

 The value of the treatise is much enhanced by the accompanying 

 plates, eight in number, comprising nearly 100 figures of the 

 foiTns of crystals obtained by the various reactions described in 

 the text. 



An International Congress of Cliniatologistsand Hydrologists 

 is appointed to meet at Biarritz during the first week in October. 

 The co-operation of the various medical, hydrological, and 

 meteorological societies of France has been received ; the 

 Minister of Commerce will open the first meeting on October i, 

 and Dr. Durand-Fardel of Paris will be the President. The 

 object of the Congress will be to assemble specialists from every 

 country to discuss questions connected wdth hydrology and 

 climatology. Excursions are to be made to various watering- 

 places in the Pyrenees. 



The sale of a" considerable portion of the celebrated Godcffroy 

 Ethnological Collection from the South Sea Islands, at Hamburg, 

 to the Leipzig Museum, has already been recorded. The 

 portion thus sold appears to have been mortgaged by the owner, 

 and the sale was made by the mortgagees. The remaining part, 

 which was not mortgaged, and which included very valuable 

 zoological and palreontological collections, as well as a compre- 

 hensive collection of woods from the South Seas, has just been 

 purchased by the city of Hamburg for 85,000 marks. 



Mrs. Ogilvie, of Sizewell House, has presented 1300/. to 

 the Ipswich Museum, to clear off the debt attaching to the 

 building. 



The Municipal Council of Paris at its sitting of the 29th ult. 

 resolved to vote a sum of 5000 francs to M. Georges Poucher, 

 to enable him to continue his investigations into the course of 

 Ihe Gulf Stream. 



The additions to the Zoological Society's Gardens during the 

 past week include a Macaque Monkey (Macacus cynomolgus 9 ) 

 from India, presented by Mrs. Carter ; a Black-eared Marmoset 

 {Hapale penicillata) from South-East Brazil, presented by Mr. A. 

 Evershed ; two Three- toed Sloths {Bradyfus tridactylus) from 

 British Guiana, presented by Capt. Hicks ; a Crested Porcupine 

 {Hystrix cristata) from Ceylon, presented by Miss C. S. Simp- 

 son ; a Crested Porcupine {Hystrix cristata) from South Africa, 

 presented by the Rev. G. H. R. Fisk, C.M.Z.S. ; a Black- 

 backed Jackal (C««/V 7ursome!as) from South Africa, presented 

 by Mr. John Hewat ; an Indian Antelope {Antilope cervicapra) 

 from India, presented by Capt. J. C. Robinson ; a Herring Gull 

 {Lurus argeiUatiis)^ British, presented by Capt. H. G. Alex- 

 ander ; a Ceylonese Hanging Parrakeet (Loriculiis asiaticus) 

 from Ceylon, presented by Mr. C. W. Rosset ; a Clouded Tiger 

 {Felts macroceiis] from Assam, a Burchell's Zebra {Equus 

 burchelli i ) from South Africa, two Globose Curassows {Crax 

 gloHcera 9 9) from Central America, deposited ; two Black- 

 footed Penguins {Spheniscus demersns) from South Africa, pur- 

 chased ; a Lesser Koodoo {Slrepsica-os imberbis £ ) from Somali 

 Land, a Ruddy Sheldrake ( Tadorna casarca), European, received 

 in exchange ; two Black-backed Jackals (Gj«;> mesomelas), an 

 Eland {Oreas canna t), born in the Gardens. 



OUR ASTRONOMICAL COLUMN 

 Parallax of Nova Andromed.^. — Prof. Asaph Hall, 

 writing under date February 12, in the American Journal of 

 Science, states that this star was then very near the limit of visi- 

 bility in the great refractor of the Washington Observatory. It 

 had thus in five months faded down from " the limit of visibility 

 to the naked eye to that in a 26-inch telescope." Led by the 

 suggestion of Prof. Peters that it would be interesting to test the 

 parallax of such a star, Prof. Hall began on September 29 a 

 series of measures of the Nova, referring it by means of polar 

 co-ordinates to a known star of the eleventh magnitude, distant 

 from it a little less than 2'. The measures do not, in Prof. 

 Hall's opinion, show any proof of a parallax, though they indi- 

 cate perhaps a diminution of the apparent distance from the com- 

 parison star. The variation in the brightness of the star would, 

 however, be likely to affect the measures. The star was too 

 faint for the measures to be continued after February 7. 



Prof. Hall mentions favourably Mr. \V. H. Monck's sugges- 

 tion {Oliserralory, vol. viii. p. 335) that the Nova may have 

 been a swiftly-moving star "that in rushing through the nebula 

 had been set on fire like a meteor in our atmosphere." 



M. Lcewy's Method of Determining the Elements 

 OF Refraction. — Mr. Gill, writing on the subject of M. 

 Lcewy's proposal to determine the elements of refraction 

 by means of a reflecting prism placed in front of the object- 

 glass of an equatorial (Nature, vol. xxxiii. p. 303), whilst 

 expressing his appreciation of the merits of the French 

 sa7'ant's scheme, suggests that, in place of having the 

 tube of the telescope fixed and the prism movable with respect 

 to it, it would be better to have the prism rigidly attached to the 

 objective, the micrometer threads being parallel to the line of 

 intei'section of the reflecting surfaces of the prism, and the whole 

 tube capable of rotation round its axis. By this arrangement a 

 sufficiently firm connection would be established between the prism 

 and themicrometer, and the necessity of calculating the direction of 

 the line of measurement bythelatterwouldbeentirelyobviated. It 

 is also pointed out by Mr. Gill that the carrying out of M. Loewy's 

 plan necessitates the construction of a complete special appara- 

 tus, but that it would be comparatively easy to adapt the modern 

 heliometer to this kind of observation. It would only be neces- 

 sary to mount the prism symmetrically in front of the object- 

 glass, so that the line of intersection of the reflecting surfaces 

 should be at right angles to the line of section of the object- 

 glass, and to the axis of the heliometer. The observations 

 would then be made by bringing the images of the two stars 

 into coincidence near the centre of the field by symmetrical 

 movements of the segments of the objective, as in the ordinaiy 

 process of measurement with this instrument. This method of 

 observation is, in Mr. Gill's opinion, the most convenient and 

 the most accurate of all those known at the piesent time, and 



