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NATURE 



\Oct. 24, 1889 



results of his own observations during the time he lived with the 

 natives as one of themselves. He found them to be undoubted 

 cannibals, and predicts their early extinction. 



One of the most original and scientific papers in the Section 

 was that of Dr. Guppy on the south coast of West Java. The 

 author dealt with a part of Java which has not been much de- 

 scribed. It is one of the least familiar portions- of this large 

 island, a circumstance due partly to its paucity of anchorages and 

 to the difficulty in landing ; partly to its having been allowed to 

 become in some places a kind of menagerie ; and partly, also, to 

 the fact that it lies remote from the 4;hief seats of government. 

 Now that the Netherlands Indian Government are rapidly carry- 

 ing out their systematic survey of the Preanger Residency, it will 

 not be long before the south coast of West Java will be much 

 better known than it is at present ; and the recent extension of 

 the central railway to Garoet and Tjirajap will do much to effect 

 this end. The author's tracks over West Java would make a 

 chequered pattern on a map ; but he has thought it best not to 

 refer to localities already well known — localities which are now 

 yearly visited by hundreds of visitors. Taking the central rail- 

 way as his base, he performed nearly all the distance on foot, 

 walking about 560 miles in all. In the paper he endeavoured to 

 give a general idea of this south coast alone. The huge volcanic 

 cones were landmarks to him, and nothing more ; they had been 

 well described by Junker and others, so he resisted the tempta- 

 tion of climbing them, and reserved his main efforts for the 

 examination of the little-described and remote south coasts of 

 the Preanger and Bantam Residencies. The object he had in 

 view was to ascertain what physical evidence there was for the 

 belief that the west end of Java was originally united with 

 Sumatra. In this paper the author showed that all the evidence 

 on the Java side of the Sunda Strait points to the opposite con- 

 clusion. Zoological evidence cannot be held sufficient to establish 

 I he previous connection between two islands without the physical 

 evidence of such a change. The problem, as usually stated, 

 seems to begin at the wrong end of the matter. Given the 

 present distribution of plants and animals, it is then attempted to 

 explain the previous arrangement of the land, and this is done 

 -too often without appealing to the physical evidence at all. In 

 tracing geographical changes in the past, it would seem more 

 reasonable to adopt an opposite method ; but in the great 

 majority of cases affecting the distribution of animals, it would 

 be wiser in the first place to assume the stahis quo, and fall 

 back when that fails on the physical evidence of the presumed 

 changes. 



As was rightly pointed out by Mr. H. J. Mackinder, Dr. 

 Guppy's apparent contempt of the argument from zoological 

 distribution is to be deplored. Hitherto it has been regarded, 

 and rightly so, by the ablest biologists and geographers, as one 

 of the surest and most valuable keys to past geographical condi- 

 tions ; and it will require much more powerful arguments than 

 Dr. Guppy was able to adduce in his paper to cast it aside. 



In a paper on recent explorations in Peru and Bolivia, Mr. H. 

 Guillaume described the efforts which have been made by 

 Peruvian and Bolivian explorers and traders to open up the 

 rivers and the dense forest country lying between them. Colonel 

 Labre since 1872 has been endeavouring to open communication 

 from the Purus to the Beni. He explored the River Itury and 

 its affluents several times, as to the character and navigability of 

 which he has contributed much new information. Padre Nicolas 

 Armentia explored the Madre de Dios in 1885, and resided for 

 some time in the country of the Araonas Indians. From its 

 mouth for 280 miles the river receives no important tributary ; 

 the Padre believes it has a navigable course of 400 miles for 

 steamers. Mr. Guillaume described in detail the gold-bearing 

 region at the source of the Madre de Dios. He then referred 

 to the explorations of Senor Carlos Fry on the Ucayli and its 

 tributary, the Urubamba, 



Mr. Theodore Bent's paper, on his recent visit to the Bahrein 

 Islands in the Persian Gulf, was a contribution of some origin- 

 ality on the present condition, the antiquity, the inhabitants, 

 and past history of this interesting group. Dr. Nansen's paper 

 -on Greenland was identical with that given to the Geographical 

 Society, and already reported in Nature. 



The Report presented to this Section by Mr. Joseph Thomson, 

 on the geography and geology of the Atlas Mountains, can 

 hardly be said to contain anything that has not already appeared 

 in his narrative, except the lists of plants and of Coleoptera. 



On the whole, it will be seen that the Geographical Section 

 has not a very brilliant account to render. 



THE MECHANICAL PAPERS AT THE 

 BRITISH ASSOCIATION. 



A MONG the papers read in Section G, after th? President had 

 ■^ delivered his address, was one by Mr. Alex. C. Humphreys, on 

 water-gas in the United States. Water-gas is produced by the 

 decomposition of steam by incandescent carbon. The two ways 

 of effecting the decomposition, the intermittent and continuous, 

 were described. In the first a cupola furnace is used : a blast of 

 air raises the fuel to the necessary temperature ; when this is 

 effected the air is cut off and steam turned on, the blowing in of 

 air and steam occurring intermittently. In the continuous pro- 

 cess, steam is passed uninterruptedly through retorts containing 

 carbon, which are heated externally, or steam and air are forced 

 in continuously through a cupola furnace ; but the latter process 

 has the disadvantage of the resultant gases containing nitrogen. 

 Water-gas has no light-giving properties so that it has to be 

 carburized for illuminating purposes, or employed to raise some 

 solid substance to a white heat. The different processes in vogue 

 were described, and their theory explained. In conclusion the 

 author gave expression to the belief that the day of gas, fuel- 

 gas, was rapidly approaching ; that even the great rival of gas, 

 the electric light, may yet be dependent on it for the cheapest 

 means of producing the electric current. Then will the gas 

 engineer and the electrical engineer, shoulder to shoulder, be 

 striving to correct the present wasteful strains on Nature's store- 

 houses. 



Precautions to be adopted when the electric light is supplied by 

 means of transformers, by Mr. Killingworth Hedges. In a paper 

 the author read at the Southport meeting of the British Associa- 

 tion, he urged the necessity of regulations, and the adoption of 

 proper safety appliances, in connection with electric lighting. In 

 this paper he refers to the danger incurred when currents of high 

 tension are converted into pressures suitable for incandescent 

 lamps by means of transformers. The precaution necessary in 

 such cases is either to earth the secondary circuit — which, how- 

 ever, has certain disadvantages — or to connect one or both of the 

 leads to a safety appliance, which would automatically divert any 

 excess current to earth, and at the same time shut off the supply 

 in that portion of the faulty circuit by the fusion of the lead wire 

 or mica-foils in the main cut-outs. Numerous experiments have 

 been made with a vacuum protector, designed by the author, to 

 ascertain the distance which an alternating current of high 

 E.M.F. will leap across the two electrodes, which were fixed 

 in the opposite ends of a glass tube from which the air had been 

 partially excluded. The results differ from those observed by 

 De la Rue with continuous currents ; the following phenomenon 

 was noticed — that the arc, after starting between the two points, 

 almost invariably extended itself to a bow-shape and ran back to 

 the base of one or both of the platinum electrodes, one of which 

 nearly always fused, leaving the other intact. 



Electric launches on the Thames, by Prof. G. Forbes, F.R. S. 

 Launches are chiefly wanted in the summer ; to prevent injuries 

 to banks the speeds should not be high, so that a comparatively 

 small supply of accumulators is required. The author experi- 

 mented with the Delta, 33 feet long, 6 feet beam, fitted with 

 forty-four cells, weighing 2520 pounds. She is steered by a 

 wheel in front within reach of three handles required to work 

 her. The first is to put the current on or off; the second for 

 half or full speed, and the third for going ahead or astern. The 

 first is mechanically locked with the others, so that they cannot 

 be moved without first cutting off the current. Fusible cut-outs 

 are inserted to prevent injury to the motor if the propeller be- 

 comes jammed. The batteries are under the seats on each side 

 of the boat, thus leaving clear space for passengers, of which 

 she could carry twenty. The pull at full speed gives i '44 horse- 

 power, or 1074 watts, including electrical losses, slip, and all 

 friction. The average pressure at the motor terminals during 

 the run was 78 volts, and the average current 23 amperes, which 

 gives 1794 watts expended. This gives a total efficiency of 

 60 per cent. The author suggested that negotiations should be 

 opened with the Thames Conservancy to establish charging 

 stations, as there was likely to be a great demand in the future 

 for electric launches. 



Series electrical traction (Northfleet Tramways), by Mr. 

 Edward Manville, M.Inst.C.E. The economical distribution 

 of electrical power over long distances involves the use of a 

 current of high potential, and by running the motors in series 

 the advantages of high potential are secured. The main features 

 of a series electrical tramway are a dynamo producing a current 



