July 28, 1881] 



NA TURE 



295 



new instruxoent two copper plates are suspended in an electro- 

 lytic cell containing sulphate of copper in solution, and placed in 

 a branch circuit through which a known fraction of the main 

 current is shunted. The copper plates are hung upon a lever 

 arm so adjusted that when by electrolysis one has grown a 

 certain amount heavier (by deposition of copper) and the other 

 grown an equal amount lighter, the lever tips up and reverses 

 the current through the cell, and at the same time moves a 

 registering dial-apparatus through one tooth. The action goes 

 on again until the tilting lever is again overbalanced, and tipped 

 back, when the current is again reversed, and another registration 

 effected. Each "tip" clearly corresponds to the passing of an 

 exact quantity of electricity through the cell, and the registered 

 indications are therefore proportional to the total consumption. 

 But -will it luork ? 



Herr Ed. Dorn has investigated the relation between the 

 absolute diameters of molecules of gases and their dielectric 

 capacity on the lines of a suggestion due- to Mos-otti, that the 

 properties of dielectrics might be explained by supposing them 

 to consist of non-conducting material, in which innumerable 

 minute particles of conducting matter are imbedded. 



Everyone knows that the very feeblest currents produce 

 audible sounds in the telephone, which is more sensitive than 

 any galvanometer to feeble currents. M. Pellat lately declared 

 that the heat necessary to warm a kilogramme of water one 

 degree would, if converted properly into the energy of electric 

 currents, suffice to produce in a telephone an audible sound for 

 ten thousand years continuously. 



GEOGRAPHICAL NOTES 



The preparations for the International Geographical Congressj 

 to be held in September next at Venice, together with a Geo- 

 graphical Exhibition, are advancing rapidly. The BoHdino of 

 the Italian Geographical Society announces in its last number 

 that the saloons for the Exhibition are already distributed among 

 the exhiliitors, and that the nations which will occupy the most 

 space will be Italy, France, Germany, Austria and Hungary, 

 Russia, and Switzerland. The saloons allowed for the Exhibi- 

 tion in the royal p.alace being insufficient, it was agreed imme- 

 diately to proceed to the construction of provisional buildings. 

 The Italian railway companies have granted a reduction of 30 

 per cent, on the prices of tickets, and of 50 per cent, on goods 

 for members of the Coi gress. The Austrian Lloyd and the 

 Navigation Company, " Rubattino e Florio," grant a reduction of 

 50 per cent, on passengers' fares. As to the questions to be 

 discussed at the Congress, the Commission has already published 

 in the Bolletino its reports on most of them. Among the ques- 

 tions are : — On the Present State of Telegraphic Determinations 

 of Longitude, by G. Lorenzoni. — On the Determination of the 

 Temperature of Sea-water at Different Depths ; on the Measure- 

 ment of Depths ; on the State of the Surveys of Coasts, &c., by 

 G. I!. Magnaghi ; on the Extinction of Aboriginal Races, by L. 

 Hugues ; and on the Teaching of Geography in Schools, by L. 

 Schiaparelli. We do not hear of any great activity in the collec- 

 tion of British exhibits for the annexed exhibition of geographical 

 apparatus, &c. In England, indeed, no great interest is felt in 

 these congresses. In Russia, on the contrary, a collection of 

 apparatus has for some time been in preparation. M. Grigorieff 

 is to represent the Russian Government and the Imperial Geo- 

 graphical Society at Venice. 



The Swedish Government has decided to send a scientific 

 expedition to Mossel Bay in the course of next year, for the pur- 

 pose of collecting meteorological information. The expedition 

 will be directed by Capt. Malmberg, and will have to remain 

 during the summer of 18S2 aud the A\inter of 1SS3, ^^ order to 

 obtain the observations of an entire year. Mossel Bay is situated 

 to the north of Spitzbergen, lat. 79'54, long. l6'i5. The locality 

 IS well known to the Swedes. Prof. Nordenskjold stayed there 

 in the winter of 1872-73 with three ships. A Swedish man-of- 

 war will take the expedition to Mossel Bay, under the command 

 of Capt. Palander, who, after having fixed the special meteoro- 

 logical station of Capt. Malmberg, will return to Sweden. 



We find in the last number of the BolUlino delta SacietH 

 Geopafica Italiana a paper on the journey of the late Signor 

 G. M. Giulietti from Zeila on the Gulf of Aden to Harar. This 

 journey was accomplished in 1879, and the narrative was in- 

 tended to form part of the complete description of all Signor 

 Giulietti's travels, but after his death M. Guido Cora published 



this small fragment with a map of the country. We notice also 

 in the same publication a paper by Prof. G. Pennesi on the 

 Italian missionaries who travelled in Lower Guinea during the 

 second half of the seventeenth centuiy ; also accompanied with 

 a small map of the country. The author speaks at some length 

 of the two most interesting journeys of P. Dionigi Carli from 

 Piacenza, and of P. Gio. Antonio Cavazzi from Montecuccolo. 



Count Waldburg-Zeil, the well-known scientific explorer, 

 started from Bremerhafen on board the steamer Luise for the 

 River Yenijei on the 22nd of last month. The journey is under- 

 taken solely for scientific purposes. Count Waldburg-Zeil intend- 

 ing to make collections illustrating the fauna of the Siberian 

 coast and the sea in that district. 



In a letter just received from the Gaboon Pere Delorme 

 reports the foundation of a mission station on the Ogowe River, 

 which the French are making peculiarly their own. The station 

 is placed at the east end of a large island in the river, called by 

 the natives Ozange-Nenge, i.e. Island of Light, which is con- 

 veniently situated for communicating with the tribes on the 

 banks of the Ogowe and the Ngunie, one of its principal affluents. 

 Immediately round the station are the Galois ; next to them, on 

 the right bank of the Ogowe, come the Eningas, while further 

 south, on the left bank, or rather on the banks of a branch of 

 the Ogowe, which goes to form Lake Ajingo, are found the 

 Adyombas. Pere Delorme expresses a decided opinion that 

 these three tribes are really one people ; they all speak the same 

 language and have the same laws. All of them are very vain 

 and voluptuous. The Galois despise agriculture, and are a 

 trading people. They go up beyond the rapids of the Ogow e in 

 search of india-rubber, ivory, and ebony. The slaves, or in 

 default of them the women, are left to attend to the cultivation 

 of manioc, banana trees, ground-nuts, and sugar-cane. 



The statement that an instalment of the Geographical Society's 

 large map of Eastern Equatorial Africa will be issued this month 

 is, w'e learn, unauthorised ; and though, probably owing to the 

 long delay which has already occurred, the propriety of issuing 

 the map in parts has been discussed, the question is still left 

 open. When ready, the map will be published by Mr. Stanford. 



The fourteenth Congress of the Italian Alpine Club will meet 

 at Milan on August 29 to September 2 next. An Alpine exhibi- 

 tion will also be held, and three excursions will be made : the 

 first to Erba in the Brianza and the grotto of Pinto, the second 

 vi& Como to Varenna on the Lake of Como, and the third to 

 Etico, coupled with an ascent of Monte Grigna. 



The death is announced of the well-known African traveller 

 Herr J. M. Hildebrandt. He died on May 29 last at Tananarive 

 (Madagascar). 



Dr. O. Finsch, the Polynesian traveller, safely arrived at 

 Sydney from New Britain at the beginning of May. He 

 stayed over eight months in New Britain, and has thence sent 

 forty-five ca-'es containing natural history collections to Berlin 

 via Hamburg. These collections consist of no less than 12,000 

 zoological specimens, a large number of anthropological objects, 

 besides a series of ethnographical specimens, surpassing in num- 

 ber and completeness any collections yet made in this field. Dr. 

 Finsch intends staying only a short time at Sydney, and then 

 proceeds to New Zealand in order to become acquainted with 

 real Maori-, for the sake of comparison with the Polynesian and 

 Mikronesian races he has studied so minutely. Afterwards the 

 traveller, in continuation of his Melanesian researches, intends 

 to visit North .-Australia to see and study the so-called Australian 

 negroes. For the same purpose he will try to stay upon New 

 Guinea for some time, as he considers the minute study of real 

 Papuans of great importance. 



News has been received from Commander van Boekhuyzen, 

 the leader of the Dutch North Polar Expedition. He writes 

 from Vardo to say that the Willem Barents could not reach 

 Spitzbergen. The ice extended in a compact mass from 68* 30' 

 N. lat. and 6° W. long, to 73° 30' N. lat. and 14° E. long., some 

 twelve geographical miles to the north of Vardo. There was 

 ice also some thirty geographical miles south of Bear Island. 

 Commander van Boekhuyzen w'ill make another attempt to get 

 northwards in 72° N. lat., and then return home after a month, 

 as he is convinced that Novaya Zemlya is completely inclosed in 

 a barrier of ice. 



Letters from Dr. W. Kobelt have just been received by the 

 Riippell Institution at Frankfort, who are the promoters of the 

 expedition. The letters are dated from Oran. Dr. Kobelt's 



