Feb. 2, .^m'] 



NATURE 



331 



(which certainly does not live on cocoa nuts there, as there are 

 none). In rough weather landing is almost" impassible on the 

 coast of the Little Andaman, and even in fine weather there are 

 heavy ground-swells and tide-rips. On the north coast large iso- 

 lated reefs and ledges exist, which make navigation dangerous. 

 With regard to the aborgines of the island, Mr. Portman is of 

 opinion that the whole of the Little Andaman Island is peopled 

 by one race, calling themselves Onges. These people are sub- 

 divided into tribes, who adhere more or less to their own villages, 

 and who quarrel and fight with each other considerably. They 

 appear healthy ; their principal diseases being chest complaints, 

 colds, fever, and itch. In physique they compare favourably 

 with the inhabitants of the Great Andaman. Their manners 

 and customs differ somewhat from those of the Great Andaman 

 people, the principal differences being the following : — Instead 

 of small lean-to's, they build large circular huts, some measuring 

 as much as 35 feet in height, and 60 feet in diameter. In these 

 huts the various families sleep on charpoys of wood and cane 

 matting, raised from 6 to 18 inches off the ground, and about 

 2 feet 6 inches square, Their habits are more cleanly, par- 

 ticularly as regards their huts, and the manner of preparing their 

 food, which is invariably cooked. They cook, dry, and store in 

 baskets, a small fish like a sprat, and this, with the boiled seed 

 of the mangrove, seems to be their principal food, which they 

 supplement with what they can. Their canoes, utensils, orna- 

 ments, and bows, are different from those of other Andamanese, 

 and the women wear a tassel of yellow fibre in place of the leaf. 

 They do not smear their bodies over with red ochre, or tattoo 

 themselves, nor do the women keep their heads clean shaved. 

 They are by no means expert in the use of a canoe in rough 

 water, and do not harpoon turtle or dugong, though very fond 

 of the former. They have no religion of any kind, and Mr. 

 Portman learnt nothing of their traditions or superstitions, 

 from which they seem even more free than their neighbours. 



Mr. C. M. Woodford has recently returned from a two years' 

 visit to the Solomon Island-, with extensive collections of mam- 

 mals, birds, reptiles, Lepidoptera, &c. Nearly six months were 

 spent on Guadalcanar, an island the interior of which has never 

 been previously explored. Ascents were made of several rivers, 

 the furthest point reached being about fifteen miles from the coast ; 

 but the hostility of the bushmen prevented the ascent of Mount 

 Lammas. 



OUR ELECTRICAL COLUMN, 



Mr. Willaru Case, of Auburn, N.Y., U.S.A., whose 

 extremely interesting paper on a thermic voltaic cell was read 

 before the Royal Society on May 6, 1886, is systematically pur- 

 suing his studies to obtain electric energy direct from carbon 

 without passing through the intermediate stage of heat. A 

 paper read on January 10, 1888, in New York, narrates his latest 

 experiments. Jablochkoff tried to do it by immersing plates of 

 carbon and iron in fused nitre. Mr. Case has been using 

 chlorate of potassium and chlorine peroxide (perchloric acid), and 

 with the latter has obtained an E. M.F. with certain forms of 

 carbon varying from 0*3 to i'24 volt. 



In 1869, Dr. Gore proposed a 'thermo- magnetic generator of 

 electricity (Proc.R.S. 1868-69, P- 261), in which an increasing or 

 decreasing magnetic field was produced by heating and cooling 

 an ironnvire placed as a core to a coil of wire. Mr. Edison has 

 recently endeavoured to make this principle practical, but M. 

 Menges, of the Hague, has been more successful. The difficulties 

 to overcome are waste of heat, energy, and consumption of time, 

 in heating and cooling. The results obtained at present are, how- 

 ever, poor, though encouraging. 



M. Tereschin, following Quincke's examples and directions, 

 has found with water, methyl and ethylic alcohol, bisulphide of 

 carbon, ether, oil of turpentine, and rape oil, a considerable 

 transport of mass in capillary tubes in the direction of the 

 positive current {Beibldttir No. 10, 1887) ; and Prof. Horace 

 Lamb, in the Phil. Mag. for January, prints the admirable paper 

 on the subject which was read before Section A of the British 

 Association at Manchester last September, in which he criticizes 

 the work of Wiedemann and Helmholtz, and explains the 

 phenomenon on the assumption of Quincke, that there is a 

 contact potential difference between the fluid and its solid 

 boundaries, and his own conclusion that there is a sliding 

 coefficient for a fluid in contact with a solid. This transport of 



mass, due to currents, and the electromotive forces produced by 

 the passage of liquids through capillary tubes, and porous 

 diaphragms are facts undeveloped and unapplied at present. 



Considerable attention is being devoted to the heating and 

 fusmg of wires by currents. Sh )rt lengths of fine wire are used 

 in nearly all electric light equipments as safety valves or cut 

 outs ; but the law determining the behaviour of these fuses was 

 little known. Mr. Preece has written two papers for the Royal 

 Society. Profs. Ayrton and Perry introduced the subject in a 

 recent paper read at the Society of Electrical Engineers, and 

 Mr. Cockburn has brought the whole subject before that Society, 

 where it has been well threshed out. For fine wires, viz. those 

 under -oio in., the fusing current varies with the diameter; 



but for wires over 'oio in., is given by the equation 



C = «r/3/2. 

 The constant a has been determined for all metals. The 

 behaviour of tin, which is very commonly used, is peculiar. 

 When it approaches the temperature of fusion, its surface 

 oxidizes and coats the wire with a thin skin, which acquires a 

 higher temperature and allows a greater current to flow before 

 fusing. Mr. Cockburn breaks through this skin with a weight 

 —a pellet of lead ; while Mr. Preece prevents the skin forming 

 by covering the wire with shell-lac, which acts as a flux and 

 prevents oxidation. 



Major King, U.S.A., has recently made a mammoth 

 electro-magnet out of two Rodman guns, weighing about 60 

 tons. It was excited by a powerful dynamo, and the armature 

 resisted a pull of neariy 10 tons. The field was felt and 

 watches were stopped at very great distances. 



Von Bernardo's system of welding by directing an arc 

 itself along the crack, fissure, or edge of the metal to be welded 

 is attracting great attention on the Continent. Prof. Ruhlmann, 

 of Chemnitz, has read a very interesting paper before the Electro- 

 technical Society of Beriin. A carbon rod is the positive and 

 the metal to be fused the negative pole of the arc. The arc acts 

 like a blow-pipe flame. It is eminently adapted to repair cracks 

 and leaks in boilers, heaters, and condensers, to repair tools and 

 generally to cover the ground of soldering and welding. 



A novel mode of forming electrolytically deposited copper 

 tubes is attracting considerable attention. The copper is slowly 

 deposited in a thin coating on an iron mandril kept constantly 

 rotating in the bath. As the copper forms it is pressed by an 

 agate burnisher, which compresses the molecular structure into 

 a hard and solid mass of great tensile strength. Such copper 

 has reached a breaking strain of 40 tons on the square inch. The 

 process is due to Mr. W. Elmore. 



A curious experiment is mentioned by the Electrician 

 (January 27). A disk of soft iron has a spindle put through it so 

 that it can be spun like a top. When at rest or moving slowly 

 the disk is attracted by the poles of a magnet ; but when it turns 

 with sufficient velocity it is repelled by the magnet. The re- 

 action of the induced currents in the mass of the metal is greater 

 than the magnetic attraction. 



H. F. Webf.r has cast doubts on the dull red rays being the 

 first luminous rays to appear. He says that the carbon filaments, 

 platinum, gold, and iron give a "gray glow," which is evident 

 at temperatures much below that of dull red, viz. 525° C. Gold 

 gives this gray effect at 417°, iron at 377°, and platinum at 390°. 



THE PROPOSED TEACHING UNIVERSITY 

 FOR LONDON. 



HTHE following is the text of the petition which has been 

 -*■ drawn up by the Association for Promoting a Teaching 

 University for London : — 



To the Queen's Most Excellent Majesty in Council. 



The Humble Petition of the Association for Promoting a 

 Teaching University for London 



Showeth — 



I. That the Association for Promoting a Teaching University 

 for London was formed in 1884, and has enrolled up to the 

 present time about 250 members, each of whom was specially 

 invited to join on the ground of eminence, or of experience in 

 matters affecting University teaching in London, or of being 



