March 



Oi 



1890] 



NATURE 



447 



at work throughout every clear night. The number of 

 photographs obtained is 1155. The objects photographed 

 are selected from a list of 625 double stars, 143 clusters 

 and other celestial bodies, such as the moon and planets. 

 As these same objects have been'repeatedly photographed 

 at Cambridge with the same instrument, an accurate com- 

 parison of the atmospheric conditions of the two places 

 may be made. It will of course be impossible to derive a 

 final conclusion until the observations have extended over 

 at least a year, but the evidence already secured shows 

 that in summer results can be obtained at Wilson's Peak 

 which cannot be obtained here. The difference is very 

 pronounced for such objects as the markings on Jupiter. 

 Clusters like that in Hercules are well resolved, so that 

 the individual stars are easily measured, which cannot be 

 done with the best Cambridge photographs. As a test- 

 object the sixth star in the trapezium of the Orion nebula 

 is clearly photographed for the first time. A new variable 

 star has been discovered in the midst of the cluster G. C. 

 3636. A beginning has been made of the measurements of 

 the position and brightness of the double stars, and it is 

 hoped to extend this work to the clusters, and thus furnish 

 an extensive addition to this department of micrometic 

 astronomy. 



Much experimental work has also been done at Cam- 

 bridge, as is shown by the fact that nearly a thousand 

 photographs have also been taken there. Moreover, the 

 expedition to Peru is largely supported by the Boyden 

 Fund. The meridian photometer will be used to extend 

 two large series of observations to the south pole. These 

 are the " Harvard Photometry," and the zones used in the 

 revision of the Dtcrchniusteriing. This work will furnish 

 photometric magnitudes of stars as bright as the ninth 

 magnitude in all parts of the sky. The Messrs. Bailey 

 have observed 67 series, one of them including 293 stars. 

 In all, during less than six months, about 6700 stars have 

 been observed, which have required 26,800 settings. 



The Bruce Photographic Telescope. — For the last six 

 years experiments have been in progress here on the use 

 of a photographic doublet in the preparation of maps of 

 the stars. The eight-inch telescope now in Peru is of this 

 form and was mounted here in 1885. Since then 4500 

 photographs have been taken with it. With an exposure 

 of-an hour twice as many stars can be photographed as 

 are visible with a telescope having an aperture of fifteen 

 inches, and as many stars as can be photographed in the 

 same time with a telescope of the usual form having an 

 aperture of thirteen inches. Moreover with a doublet a por- 

 tion of the sky covering twenty-five square degrees can be 

 photographed with good definition, while only three or 

 four degrees can be covered equally well with telescopes 

 of the usual form. The time required to photograph the 

 entire sky will be reduced in the same proportion. With 

 a doublet each hemisphere could be covered in one year 

 with eight hundred plates. In 1885 it was proposed to 

 photograph the entire sky with the eight-inch telescope, 

 enlarging the plates three times. The results would 

 resemble in scale and size the charts of Peters and Cha- 

 cornac. The generous aid of Miss Bruce mentioned 

 above will permit this result to be attained in the original 

 photographs, without enlargement. A contract has been 

 made with Messrs. Alvan Clark and Sons for a telescope 

 having an aperture of twenty-four inches and a focal 

 length of eleven feet. Meanwhile nineteen foreign Ob- 

 servatories have united in an Astrophotographic Congress 

 to prepare a map of the stars to the fourteenth magnitude 

 with telescopes of the usual form having apertures of 

 thirteen inches. The plans have been matured with 

 great care and skill. The courteous reference to the 

 Bruce telescope and its proposed work by Admiral 

 Mouchez shows that both plans can be carried out with- 

 out disadvantageous duplication. Doubtless each plan 

 will possess certain advantages over the other. The 

 Bruce telescope will be especially adapted to studying the 



very faint stars. It is hoped that those of the sixteenth 

 magnitude and fainter can be photographed. Its principal 

 use will probably be for the study of the distribution of the 

 stars, for complete catalogues of clusters, nebula;, and 

 double stars, and for the spectra of faint stars. The 

 amount of material accumulated will be enormous, and the 

 best method of discussion will form a very difficult and 

 important problem. 



NOTES. 



The bulletins relating to the health of Sir Richard Owen, 

 who is suffering from a paralytic stroke, have called forth many 

 expressions of sympathy from the general public, as well as from 

 men of science. Hopes of his recovery are entertained, but at 

 his advanced age the process must necessarily be slow. 



A CIRCULAR letter from the Conseil General des Facultes de 

 Montpellier, issued March i, 1890, and addressed to the chief 

 learned bodies, sets forth that on October 26, 1289, a Bull of 

 Pope Nicolas IV. " erigeait en Studium gcnerale les Facultes de 

 Droit, de Medecine et des Arts, qui existaient deja depuis long- 

 temps dans notre ville." It is proposed, therefore, as we have 

 already noted, that during the present year the University shall 

 commemorate its entry upon its seventh century. The fcle will 

 probably be held towards the end of May. 



After the reading of the papers at the ordinary meeting of 

 the Royal Meteorological Society on Wednesday, March 19, 

 the Fellows and their friends will have an opportunity of in- 

 specting the Exhibition of Instruments illustrating the aiiplication 

 of photography to meteorology, and of such new instruments as 

 have been invented and first constructed since the last Exhibition. 

 The Exhibition will, at the request of the Secretary of the 

 Institution of Civil Engineers, be open in readiness for their 

 meeting on Tuesday evening the iSth instant, and will remain 

 open till Friday the 2rst instant. 



An International Exhibition of Mining and Metallurgy will 

 be held this year at the Crystal Palace from July 2 to September 

 30. The Lord Mayor is the patron, the Duke of Fife the Hon. 

 President, and the list of Hon. Vice-Presidents contains the 

 names of Lord Wharncliffe, Lord Brassey, Lord Thurlow, Sir 

 Frederick Abel, Sir Alexander Armstrong, Sir F. Dillon Bell, 

 Sir Graham Berry, Sir Charles Clifford, Sir James Kitson, Sir 

 Roper Lethbridge, M.P., Sir John Lubbock, M.P., Sir John 

 Pender, Sir E. J. Reed, M. P., Sir Saul Samuel, Sir VVarington 

 W. Smyth, Sir Charles Tennant, M.P., Sir Edward Thornton, 

 Sir Charles Tupper, Sir H. Hussey Vivian, and Prof. Roberts- 

 Austen. Mr. Pritchard Morgan, M.P., is chairman, and Mr. 

 Henry Cribb deputy-chairman of the Executive Council, which 

 consists of 20 gentlemen well known in engineering and mining 

 matters. The following are the subjects likely to be included 

 within the scope of the Exhibition : — Machinery, mining in 

 gold and silver, diamonds and precious stones, ironstone and 

 iron-ore mining, the manufacture of iron and steel, lead, tin, 

 copper, and coal mining, petroleum and salt industries, and a • 

 number of other kindred subjects. Ambulance practice and 

 the condition of miners will also be illustrated. 



A general meeting of the Society for the Preservation of 

 Ancient Monuments in Egypt will be held at the rooms of the 

 Royal Archaeological Institute to-morrow (Friday), at 5 p.m. 

 Attention will be specially called to the wanton excision of por- 

 tions of the well-known fresco paintings in the tomb of the 

 Colossus on a sledge, dating from the Twelfth Dynasty, or 

 between 2000 and 3000 years B.C., at Der-el-Barsha, the 

 chipping out of cartouches of different Sovereigns from the Sixth 



