294 



NATURE 



\Atig. 12, 1875 



These Geissler tubes represent the upper part of the 

 atmosphere which becomes luminous when the aurora 

 boreahs is observed in the northern hemisphere. The 

 phenomena produced by the Lynstrom apparatus are quite 

 consistent with the theory advocated by Swedish observers 

 that electrical currents emanating from the earth and 

 penetrating into the upper regions produce aurora; in 

 both hemispheres. The experiment differs from the 





apparatus of M. De la Rive, who placed his current hi 

 vacuo, and did not show the property of ordinary atmo- 

 spheric air of allowing to pass unobserved at the pressure 

 of 760 mm. a stream of electricity which illuminates a 

 rarified atmosphere. The experiment is most attractive, 

 and hundreds of persons witness it every day. 



The arpangements for the general daily meetings of the 

 Congress are very good. Every morning the seven sec- 

 tions meet at nine o'clock and discuss the subjects 

 placed on the ordre dii jour. At three o'clock all the 

 members meet in the Salle des Etats, under the presi- 

 dency of one or other of the presidents of the various 

 geographical societies of Europe. No discussion takes 

 place at these general meetings, but the presidents of 

 sections report on the discussions which have taken place 

 at the morning sitting. Consequently, all who attend the 

 evening meeting obtain a summary of the transactions 

 of the day. Visitors are admitted to the general meetings 

 only. Sometimes several sections meet together in the 

 morning to deliberate on subjects of common interest, and 

 general deliberations will be proposed at the end of the 

 session. 



A subject v«ry much discussed has been the adoption 

 of a first meridian. Struve proposed Greenwich. One of 

 the most interesting questions has been on the substitu- 

 tion of the centesimal for the sexagesinvaf division of the 

 quadrant, or of the entire sphere. It was decided by 

 twenty-three to seven in favour of the centesimal division 

 of the quadrant, reserving the larger question of its exten- 

 sion to the entire sphere till the matter is brought before the 

 general meeting. The present system found no advocate. 

 M. Bousquet de la Grie's proposal for dividing the compass 

 into 360 points, to be reckoned from left to right, has also 

 been approved. 



The question'of ascending currents in the atmosphere 

 has been seriously discussed, M. Faye maintaining that 

 only descending waterspouts have been observed. M. 

 Faye's theories, however, have found very little support. 

 The general opinion, as supported by Mohn and others, 

 being that no descending current can be observed with- 

 out an ascending one, so that there is a circular rotation 

 of the atmosphere in altitude, and the upper strata are in 

 constant communication with inferior strata of the atmo- 

 sphere. 



A commission has been appointed on the question of a 

 great Transiberian railway. The Russian colonel Bog- 

 danovitch spoke in favour of a line by Ekaterineburg and 

 Tiumen, which has the advantage of putting Europe into 

 communication with the large rivers of Southern Siberia. 

 He said that the Russian government had decided upon 

 the construction of a section 1,000 miles long. 



Lectures were delivered by MM. Gerard Rohlfs, Nach- 

 tigall, and Schweinfnrth, on the exploration of Central 

 Africa, and these intrepid explorers answered a number 

 of questions in reference to their travels. 



On Sunday about 300 members, amongst them a num- 

 ber of ladies, visited Compiegne to see the museum of 

 Cambodian antiquities, collected by M. Delaporte, a 

 lieutenant in the French national service, and exhibited 

 in the ex-imperial palace inhabited by Napoleon III. M. 

 Delaporte pubhshed in 1873, atj Hachette's, a large work 

 in two folio volumes, with an immense number of 

 illustrations, and a graphic atlas in chromolithography. 

 The King of Cambodia, having been admitted to a 

 French protectorate, sent a number of antiquities to Com- 

 piegne, where M. Delaporte has organised the museum 

 which was visited on Sunday. M. Delaporte himself 

 was in attendance to explain the manner in which all 

 those astonishing relics of an unknown part had been 

 brought to light. These monuments have undergone a 

 systematic destruction, it is supposed, in the fifth cen- 

 tury B.C., and are mostly concealed in the centre of im- 

 mense forests which have grown since that time, and 

 situated in infested districts which are mostly inhabited by 

 tigers and poisonous snakes. It was M. Jules Simon 

 who had the honour to grant the mission vvhose results 

 have been so fruitful, and the zeal elicited by explorers 

 was so great that the credit of 10,000 francs granted was 

 almost sufficient to collect a quantity of stones which fill 

 the basement of the Palace. 



Of the juries appointed by the Geographical Congress 

 five have given their awards, while the remaining two 

 have not yet come to any decision. Letters of distinc- 

 tion, the highest reward the Congress can bestow, have 

 been conferred upon England— namely, in Group i upon 

 the Topographical and Trigonometrical Office of India 

 and the Ordnance Survey Office of Southampton ; in 

 Group 2 upon the Hydrographic Office ; in Group 3 upon 

 the Meteorological Office, the office of Geological Survey 

 of Great Britain, and the Royal Geographical Society of 

 London ; in Group 4 upon the Palestine Exploration 

 Fund for maps and plans and photographic reliefs. 

 Letters of distinction have also been conferred in the United 

 States upon : Group 2 the Navy Department ; Group 3 

 the United States Signal Service, and upon Mr. William 

 Martin for a description of the island of Hawai. Nu- 

 merous first-class medals have, moreover, been conferred 

 upon EngUshmen and Americans. 



THE MANATEE AT THE ZOOLOGICAL 

 GARDENS 



OF those mammalian animals which, instead of making 

 their customary abode the land, reside in water 

 either fresh or salt, the Seals and Porpoises are best 

 known by sight to the public at large. These two just 

 named animals are representatives of two great zoological 

 groups, the Pinnipedia and the Cetacea, the relationships 



