46 



NATURE 



l^May 9, 1878 



merchant service to obtain and bring home information 

 that would be useful to science, and might, by means of 

 lectures and otherwise, foster a scientific spirit among 

 our commercial population. Much good is done in this 

 way, we believe, by the societies of Marseilles, Bordeaux, 

 and Lyons. Two new geographical societies have, we 

 learn, been established in France, at Metz and Montpellier. 

 The French are evidently doing their best to remove the 

 reproach so frequently cast at them, of being more 

 ignorant of geography than even the English. 



That the Continental societies go in for earnest work is 

 evident from the weighty journals published by most of 

 them. The Mittheilungen of the Hamburg Society for 

 1876-77, for example, is a thick volume of 400 pages, 

 containing a number of papers of considerable scientific 

 value. Besides several papers on Central and South 

 Arnerica, there is a long series of letters by Dr. Pfund, 

 filling nearly half the volume, written during his travels 

 in Kordofan and Darfur, along with Colonel Prout, of 

 the Egyptian staff. Other African papers are by Dr. 

 Paul Ascherson on his travels in the Lybian desert in 

 1876, and one of much value by Herr Fischer, on the 

 present condition of the Galla Country. In the Deutsche 

 Geographische Blatter, the organ of the Bremen Society, 

 Dr. Oskar Lenz discusses at length the trade con- 

 ditions in Equatorial West Africa, with special reference to 

 Stanley's discoveries ; Dr. Lenz does not believe that the 

 Ogovai is connected with the Congo. Mr. W. H. Dall is 

 contributing to this journal a series of papers on his own 

 and other recent researches in the Aleutian Islands, 

 while Dr. A. Ziegler has an interesting paper on Regio- 

 montanus and Martin Behaim. Turning to Italy the 

 energetic Roman Society has begun the publication 

 (apart from their always interesting Bo/tetmo) of Memori'e, 

 containing at length the most important papers read at 

 the Society's meetings. The first part contains a lecture 

 by the president, Signer Cristifero Negri, on scientific 

 geography, which shows what has more than once been 

 said, that geography is really the meeting-place of all the 

 sciences. Then there is a paper on the geographical 

 distribution of camels, by Prof. Luigi Lombardini, and 

 a well-arranged series of instructions to explorers by 

 various specialists, edited by Signor A. Issel. Nor must 

 we forget the American Society, with its seat at New 

 York, and which is the medium for a good deal of valu- 

 able information that might not otherwise reach the light 

 of day. Chief-Justice Daly's presidential address always 

 contains an admirable and exhaustive summary of the 

 year's work ; and this year it is quite as full and interest- 

 ing as usual, nothing in the domain of geography of any 

 importance remaining untouched, special prominence 

 being of course given to the various surveys of the 

 United States. Thus it will be seen, that under the 

 name of geography, much varied and really valuable 

 work is being done, and that dilletanteism has really but 

 a small place in it, at least abroad. 



An expedition, comprising twenty-five miners and 

 others, has started for New Guinea. This news is tele- 

 graphed from Sydney, and we earnestly hope that the 

 expedition is under proper direction, both for the sake of 

 the natives, who have so far been friendly to white men, 

 and for the sake of further scientific discovery. 



THE TRANSIT OF MERCURY 

 HTHE weather on Monday was so unfavourable that 

 -■• the observations of this interesting phenomenon 

 ■were mostly unfortunate in England. In France some 

 valuable observations seem to have been made. Our Paris 

 Correspondent writes that the observations taken by M. 

 Janssen at Meudon Observatory were wonderfully suc- 

 cessful considering the state of the atmosphere. He was 

 able to make use of spectrum analysis in order to deter- 



mine the composition of Mercury's atmosphere. He was 

 able to see Mercury before it had begun to make its first 

 entrance on the disc. This observation is a confirmation 

 of the phenomena observed in 1874 at Yokohama on the 

 occasion of the Transit of Venus. Two photographs are 

 excellent, and will lead to a determination of the diameter 

 of the planet. At the Paris Observatory the transit was 

 also seen. 



When Capt. Mouchez saw Mercury the disc had been 

 indented to the extent of 1" of degree, about |th diametes 

 of Mercury. When it was seen by the brothers Henry it 

 was half on the disc. The difference of time is about 10" 

 later at the National Observatory. The brothers Henry 

 also saw the interior contact at about 3h. 23m. and some 

 seconds. The exact time cannot be given yet. The con- 

 tact was decidedly bad owing to the clouds. 



At Algiers and Bordeaux the observations were bad. 

 At Ogden, Utah, United States, the delegates sent by 

 the French Government, M, Andr^, of Lyons, and M. 

 Angot, of Paris, obtained seventy-eight photographs of 

 the transit. Satisfactory observations and photographs 

 of the transit were taken at the Government Observatories 

 at Washington and West Point, U.S. 



Mr. J. J. Cole writes to the Titnes from Mayland, 

 Sutton, Surrey, that the sun was clear from 3.5 to 3.25, 

 and the whole ingress was steadily observed with a 

 refractor of 6 inch aperture and three others smaller. The 

 Greenwich mean times of external and internal contact 

 were taken, and were confirmed by Mr. Bawtree near 

 with unexpectedly small differences. 



At Aberdeen the transit was observed by Lord Lindsay, 

 Mr. Ranyard, Dr. Copeland, Mr. Carpenter, and Herr 

 Lohse, and photographed by Mr. Davis, A thin cloud 

 covered the sun at the time of first contact. No ring of 

 of light was seen round the part of the planet off the 

 sun' s disc. External contact was observed spectroscopic 

 cally by Lord Lindsay, who detected the approach of the 

 planet by the eclipse of the C line thirteen seconds before 

 its limb encroached upon the continuous spectrum of the 

 photosphere. Mr. Ranyard observed the continuous 

 spectrum below C line, but saw no trace of the planet 

 until it was on the sun's disc. No change in the solar 

 spectrum was observed at the limb of the planet. Dr. 

 Copeland, Mr. Carpenter, and Herr Lohse obtained both 

 contacts and measures of diameter. 



Mr. C. G. Talmage writes as follows to the Times from 

 Mr. Barclay's Observatory, Leyton, Essex ; — 



" Owing to the prevalence of clouds the times of ex- 

 ternal and internal contact at ingress were not observed 

 here. The first view I obtained was at 3.43, Avhen Mercury 

 had advanced some considerable distance on the sun's disc. 

 The duration of clear sky was then so short that there 

 was not sufficient time to obtain micrometrical measures of 

 distance from the sun's limb. For about eight or ten 

 seconds the sky was absolutely clear, and then I noticed 

 that Mercury was surrounded by a bright ring, dark- 

 ening off to the periphery, which was exceedingly well 

 defined. The distance between the limb of Mercury and 

 periphery of ring was about two-thirds of the planet's 

 diameter. I used the full aperture of ten inches, with a 

 diagonal power of eighty." 



DE CAILLETET'S APPARATUS 



■\"\/E have already (vol. xvii. p. 265) spoken at length 

 * * of M. Cailletet's method of liquefying the last of 

 the gases, and at the same time we referred to the fact 

 that students of science in France had not been for- 

 gotten by the accomplished experimenter. We described 

 briefly a portion of an apparatus for use in laboratories, 

 for this experiment, and are now able to give an illus- 

 tration of the complete laboratory apparatus as manur 

 factured by Ducretet and Co., of Paris. The figure 

 shows the apparatus one-eighth the size of reality. 



