May 6, 1880] 



NATURE 



19 



Eyck by the deposition of copper electrically upon the clay 

 model. The production of bronzes may be readily carried out 

 on a small scale by the following process communicated to the 

 Kaliiral History Journal, and which possesses ^ome elements of 

 novelty. Take any plaster figure or group, boil in sterine, then 

 blacklead and plunge in a copper bath. Attach a very weak 

 batteiy, and deposit very slowly a thin coating of copper. Now 

 remove from the bath, and bake in an oven until the plaster 

 model shakes out in dust. You have now a very thin copper 

 reproduction of your model. Varnish this outside so as to pre- 

 vent the further deposition, and replace in the bath. The copper 

 will now be deposited on the inside surface, and you can thicken 

 up to any desired point. For this second process a much stronger 

 battery may be used. 



MM. Leclerc and Vincent have described to the Physical 

 Society of Paris an electrical iastinment which will automatically 

 record the notes played upon a piano. It can be adapted to a 

 piano of any construction. 



Cloe's thermoelectric pile has been recently improved by an 

 addition which obviates the injurious effect of sudden and 

 excessive hea'ing of the junctions arising from alteration in tlie 

 pres-ure of the gas. This safety-apparatus consists of a small 

 glass vessel about half filled with water, and closed by a cork 

 stopper, through which pass two tubes, one going to the bottom 

 and being a branch of the tube by which the gas comes to the 

 pile, while the other is shorter, and conducts any gas that may 

 pass tlirough it from the vessel to a gas-burner on another branch 

 constantly lit. If the pressure of the gas is v eak the water 

 closes the mouth of the longer tube ; if it increases the gas issues 

 in bubbles in the I'quid and rises through the shorter tube to the 

 gas jet, where it is lit. The arrangement is a sort of safety-valve, 

 and prevents the pressure from exceeding a certain amount, which 

 is regulated at will. 



M. Marcel Deprez has devised an ingenious apparatus for 

 transmitting a movement of rotation by electricity. The appa- 

 ratus is composed of a transmitter and a receiver. The trans- 

 mitter consists of two ordinary split-collar commutators set upon 

 a common axis, but adjusted at right angles to each other. The 

 receiver consists of two longitudinal armatures carrying coils of 

 wire as employed in the earlier Siemens' magneto -electric 

 machines. These also run on a common axis and in posidons at 

 right angles to one another : and they are placed in the magnetic 

 field between the poles of a permanent magnet. Currents 

 generated by a battery pass through the transmitter and are 

 conveyed by wires to the receiver. For every position of the 

 axis of the transmitter there is one position — and one only — of 

 stable equilibrium for the axis of the receiver. Hence the axis 

 of the receiver follows all the movements of the transmitter ; 

 turns at the same rate and in the same direction as the trans- 

 mitter may be turned ; and makes the same number of revolutions 

 precisely to within a quarter of a revolution. 



GEOGRAPHICAL NOTES 



The new number of the Geographical Society's Proceedings is 

 chiefly occupied w ith a narrative of Lieut. G. T. Temple's voyage 

 on the coasts of Norway and Lapland, illustrated by a map on 

 w hich the depths of the ocean are well shown in colour, and by 

 Mr. E. Hutchinson's account of Mr. Ashcroft's ascent of the 

 River Kinue last August, \\ ith remarks on the systems of the 

 Eivcrs Shary and Binue. With the latter paper is given a reduc- 

 tion of Mr. Flegel's map of the LTpper Biune from his own sur- 

 vey.^, recently issued by Hellfarth of Gotha. An interesting 

 letter from Mr. Thomson is afterwards given, furnishing informa. 

 tion as to the progress of the East African Expedition. Among 

 the geographical notes may be mentioned a summary of the mo.-t 

 recent rumours respecting PrejevaLky and a description of routes 

 from Dzungaria into Tibet. There is also an account of a visit 

 paid by Mr. Woolley, of the Connilar service, to the Island of 

 Tsushima and Corea, and of the Rev. J. Chalmers's recent ex- 

 plorations in the interior of New Guinea, in the cour-e of which 

 he traversed a considerable extent of previously unknown 

 country. The notes are followed by a communication on the 

 "Tal-Chotiali Route from India to Pishin and Candahar," fur- 

 nished by Mr. G. \V. Vyse, who v as attached to the TalCholiali 

 Field Force, in correction of previaus statements made respecting 

 tliis route 



By a note received on April 2S we learn that the Howgate 

 Arctic Expedition Bill passed the House of Representatives at 



Washington on the 15th inst., and has gone to the Senate for 

 final action. "This is a great step in advance, and augurs well 

 for Government aid to the Expedition." 



Under the title of "La Exploradora" an association has 

 been formed in Spain, through the instrumentality of Seiior 

 Don Manuel Iradier, for the exploration and civilisation of 

 Central Africa, and in furtherance of its objects commenced the 

 publication of a Boletin in March. This association proposes to 

 despatch an expedition from the west coast w ith what appears to 

 be a somewhat ambitious programme. Its starting-point would 

 be the Bay of Corisco, whence it would traverse the Sierra de 

 Cristal, and afterwards march by way of Mount Onschiko and 

 the River Eyo towards Lake Albert. If successful so far, it would 

 then visit RIount Gambaragara, in the Usongora range, to study 

 the peculiar population said to be found there. '1 hen, turning in 

 a north-westerly direction, it would make its way back to the 

 Gulf of Guinea by Lake Liba and the Cameroons River. It is 

 proposed that this expedition should start at latest during the 

 month of June, but we are not auare \\hether the necessary 

 funds for its journey of fourteen months have been provided. In 

 the course of their march it is intended that the members of this 

 expedition should devote themselves to the study of all the 

 important problems yet unsolved in the central region of the 

 African continent, and especially w hether there be any connec- 

 tion between Lake Liba and the rivers Shary and Binue. 



It is stated that the Comte de Semelle is about to return to 

 Africa, in order to undertake an exploring expedition up the 

 river Binue. 



Dr. Regel, director of the Imperial Botanical Garden of St 

 Petersburg, gave an account of the Flora of Turkestan at a 

 recent meeting of the St. Petersburg Horticultural Society. 

 Turkestan may be divided into t\\ o distinct parts — the west, with 

 a very mild climate, and the east, the climate of which is almost 

 that of St. Petersburg. The flora of Turkestan is exceedingly 

 varied, much resembling that of Central Asia ; plants proper to 

 the climate of Europe grow there in small numbers. The eastern 

 part abounds in Alpine specimens, and in general its vegetation 

 approaches that of Europe, although quite as often plants are 

 met \\ ith \\ hich are the sole product of Central Asia. Turkestan 

 possesses neither lily nor tulip, and has very few conifers. 



Last week we referred to Mr. E. Whymper's mountaineering 

 exploits in South America. Some further details are given by 

 Mr. Whymper himself in a letter to Mr. F. F. Tuckett in 

 Tuesday's Times. It is dated from Quito, March l8. He 

 says:--"Vou will be glad to hear that I have succeeded in 

 polishing off Chimborazo, Corazon, Sincholagna, and Antisana. 

 We have also passed twenty-six consecutive hours on the top of 

 Cotopaxi. This last I reckon a feat, and I am not aware that 

 any one has ever before encampied at so great an altitude as 

 19,500 feet. Antisana is the most difiicult of those we have 

 been up, and few more difficult ascents have ever been made. 

 We are now going off to Cajambe, the mountain on the Equator, 

 and shall Xrj on the same journey to polish off .Saranen and 

 Cotocachi. Cayambe is thought to be an active volcano, but it 

 is not certain that this is the case, neither is its height well 

 determined. The height of Saranen is not known, but it is high. 

 Cotocachi is the volcano which destroyed Ibarra some years ago, 

 and is reputed to be 16,300 feet high. We have grown out ol 

 being aftected by rarefaction of the air, and can be quite gay and 

 lively at 19,000 feet. At first I was fairly knocked over by it, 

 and was rendered quite incapable. The Carrels also were nearly 

 as bad. The climate of Ecuador is the most utterly abominable 

 that can be imagined. We have not had one single day fine from 

 beginning to end, and not one view from a mountain top. An 

 hour of clear weather from 6 to 7 a. m. is the most you can reckon 

 on, and after that everything is bottled up in a mist. We carry 

 about mercurial barometers everywhere, and boil water to an 

 extent that would delight your heart." 



In the May number of their Chronicle the London Missionary 

 Society announce the departure, on April 16, of a new expedition 

 for East Central Africa, to reinforce the weakened and scattered 

 party now there. The Rev. A. J. Wookey goes to join Mr. 

 Hore at Ujiji, the Rev. D. Williams to Urambo, \\here Dr. 

 Southon now i--, and Mr. W. S. Palmer, a medical missionary, 

 to Uguha, where, we presume, he will be stationed at Mtowa, 

 near the Lukuga Creek. 



In their just-issued eighty-eighth Report the Committee of 

 the Bapti-t Mi-sionary Society summarise the efforts of their 



