Oct. 4, 1 888] 



NA TU'RE 



555 



GEOGRAPHICAL NOTES. 



A telegram from Mr. Joseph Thomson, dated Mogador, 

 September io, reports that he has been successful beyond ex- 

 pectation in his exploration of the Atlas Mountains. He left 

 Morocco city on August 27, and after being driven back from 

 the Urika Valley to the south-east of the city, he proceeded 

 eastwards, and succeeded in crossing the range southwards from 

 Imintanut into the Sus district. From Rezaya he ascended the 

 main range to nearly 13,000 feet. Mr. Thomson intended to 

 return to Hava for a few clays, and afterwards to proceed north- 

 wards to Fez, Mequinez, and Tangier, returning home about 

 the middle of December. 



The Report for 1887 of H.M.'s Special Commissioner for 

 British New Guinea, contains information of considerable geo- 

 graphical interest. This is especially the case with the Report 

 of Deputy-Commissioner Milman, who has charge of the western 

 district, lying between the Dutch boundary and the Aird River. 

 Mr. Milman refers to the discoloration of the sea about the coast 

 between Talbot Island and the Fly River, due, doubtless, to the 

 vast bodies of fresh water that empty into the sea from the Fly, Tait, 

 Katoer, Mai-Kassa, and other rivers. The Fly River, as far as it has 

 been ascended by Mr. Milman, is thickly populated with a purely 

 agricultural and hunting people, living in large communities ; 

 while some houses in the villages are over 200 feet in length. As 

 the river is ascended, traces of careful cultivation are seen here 

 and there on the banks, the gardens or plantations being kept 

 free from weeds, and planted with crotons and other bright- 

 leaved shrubs between the bananas or other fruit-trees, besides 

 being systematically irrigated by dykes cut at regular inter- 

 vals, which, filling at high water, remain full as the water 

 recedes. About 60 or 70 miles above Soomaioot several large 

 creeks or rivers join the main river, but whether they are 

 flowing into the river, or only form other mouths of this vast 

 system, remains to be proved. The shores of the Fly River, as 

 far as Mr. Milman ascended, are uniformly low, but owing to 

 its great width he is inclined to think they are not subject to 

 inundation. A tidal wave or bore, according to Mr. Milman, 

 ascends the river, but only on the right bank, which accounts 

 for previous visitors not having noticed it. A marauding tribe 

 coming from the westwards have been in the habit of making 

 attacks on the people in the neighbourhood of Sabai Island, 

 but the exact locality they come from is a mystery. Their 

 language and customs are entirely different from those of 

 the Sabai Island people. They had probably never seen 

 a white man until the Rev. E. B. Savage (who happened 

 to be at Sabai when their lights were seen on the mainland) 

 fearlessly visited their camp, and tried to hold some intercourse 

 with them. He describes them as a much lighter race than the 

 jrest of the New Guinea native^, and as having long straight 

 hair, while some of them have their nasal-bone pierced in three 

 places, into which are introduced pieces of bone or shell. They 

 appeared entirely unacquainted with fire-arms. Civilization has so 

 Far advanced at Port Moresby that a reading-room has been 

 erected, in which the Times and other English journals are kept, 

 a hotel has been opened, and a supply of water laid on by means 

 of pipes to the native village. 



A Russian scientific explorer, M. K. Nossilof, has recently 

 returned to Archangebk from Novaya Zemlya, where he 

 spent a year, from the summer of 1887 to August 1888. He has 

 brought with him rich botanical, zoological, and mineralogical 

 collections, and means to return to the island soon, as he has 

 resolved to devote five years to its exploration. M. Nossilof is 

 reported, to have discovered beds of iron, copper, coal, gold, 

 and sulphur, some of which, he believes, could be profitably 

 worked. Among other results obtained by him are many in- 

 teresting observations on the animal, especially the bird, life of 

 the island, thirteen months' meteorological observations, surveys 

 covering 2500 square kilometres of land, observations on the 

 ice- conditions of the east and west coasts, and 125 kilometres 

 of coast survey. He has, moreover, discovered three new 

 islands. . During the winter and spring, M. Nossilof undertook 

 excursions into the Kara Sea, and he hopes by-and-by to 

 undertake a series of soundings as far as the River Yenissei. 

 In the coming winter he intends to fix his station at the 

 east end of Matotshkin Schar, and to establish there a second 

 meteorological station, making excursions along the coast and 

 into the interior. 



ELECTRICAL NOTES. 



The Volta Prize of 50,000 francs has been awarded by the 

 French Institute to M. Gramme for his labours in introducing and 

 perfecting the continuous-current dynamo. The prize is given to 

 the inventor who has formed a memorable epoch in the history 

 of electricity. M. Gramme is a Belgian by birth, but a Parisian 

 by residence. He is entirely a self-taught, self-made man. 

 Although Gramme was anticipated by Pacinotti, his invention 

 was entirely independent, and Pacinolti's was completely dormant, 

 and would probably have remained hidden and unknown but for 

 Gramme's success. No one will contend that the prize has not 

 been richly deserved. 



Considerable attention has recently been drawn to some 

 experiments by Chappuis and Maneuvrier, in Paris, on the de- 

 composition of water by alternate currents. It is well to point 

 out that the whole question was thoroughly threshed out by Sir 

 W. Thomson in 1853, and his paper in the June number of the 

 Philosophical Magazine of that year gives all that is necessary to 

 know on the subject. Jamin, in 1882, showed how electrolysis 

 could be performed by alternate currents by inserting an arc in 

 circuit, the opposing E.M.F. of the arcs producing a partial recti- 

 fication of the alternate currents. Mr. J. F. Kelley has just 

 repeated the experiment in Newark, U.S.A. 



Mr. Lowrie (B. A., 1888), showed how the insertion of an 

 opposing E.M.F. in an alternating-current circuit enables electro- 

 lysis to be effected and how it could be utilized to measure the 

 electrical energy consumed in electric light installations. If a 

 decomposing cell of copper sulphate, and a constant E.M.F. 

 such as a secondary cell, be inserted in the circuit, the current in 

 one direction is assisted, while that in the reverse direction is 

 opposed, and the cell is acted upon by the difference : an average 

 current flowing, depositing copper at the same rate as if no alter- 

 nate currents were present. 0*23544 gramme of copper is deposited 

 per kilowatt-hour, or every gramme of copper deposited means 

 4'205 kilowatt-hours expended. 



Prok. Evving [Philosophical Magazine, September 1888) has 

 published, with additions, the paper read by him and Mr. Low at 

 the Manchester B. A. meeting, on the influence of a plane of 

 transverse section on the magnetic permeability of an iron bar. 

 A joint between two portions of an iron core possesses distinct 

 magnetic resistance even when the surfaces are true planes. 

 Compression reduces this resistance in the rough faces and 

 eliminates it when the faces are true planes. In all cases the 

 resistance greatly diminished as the point of saturation was 

 approached. A film of gold leaf interposed between the faces 

 and compressed has only a very little injurious effect. Compres- 

 sion, however, reduces the permeability of the solid core for 

 moderate magnetizing forces, though the contrary effect occurs 

 when the magnetization is strong. Villari found the same 

 reversal in the case of longitudinal pull, but in the opposite 

 direction. 



Lord Rayleigh (B. A., 1S88) has been endeavouring to 

 discover if an electric current flowing through an electrolyte 

 causes the velocity of light to vary through the liquid. He 

 experimented with dilute sulphuric acid. The result was negative 

 within the range of the experiment, which was extremely delicate. 

 In H 2 S0 4 diluted, one ampere per >quare centimetre does not 

 alter the velocity of light by one part in thirteen millions, or by 

 15 metres per second. 



It is estimated that in the United States there are 5351 electric 

 light plants and stations working 192,500 arc and 1,925,000 

 glow lamps, and consuming 460,000 horse-power. There are 

 thirty-four electric railways, 138 miles in length, run over by 

 223 motor cars using 4180 horse-power. 



Sir William Thomson (B. A., 1888) dealt with the 

 diffusion of rapidly alternating electric currents in the substance 

 of homogeneous conductors. The surface is affected first, and 

 the depth to which the di-turbance penetrates depends on the 

 frequency of the alternations. With a frequency of 150 per 

 second a cylindrical copper conductor is said to be penetrated to a 

 depth of 3 mm. Hence, if this be true, conductors for powerful 

 alternating currents such as are used in the Gaulard and Gibbs 

 system, should be tubes or flat bars with a thickness of 6 mm. 



Trouvelot has by photography obtained effects which lead 

 to the conclusion that flashes of lightning may last several 

 seconds. He gave his apparatus a slight horizontal displace- 

 ment, and found a broad ribbon-shaped band on his plate. 



