474 



NA TURE 



[March 14, 1901 



A REPORT of a second lecture on wireless telegraphy, delivered 

 by Prof. Braun at Strassburg, has been received. The first 

 lecture was referred to in our issue of February 2i (p. 403), in 

 which it was stated that we could not gather whether Prof. 

 Braun had succeeded in obtaining a satisfactory separation of 

 messages received at the same time from different sources. 

 From the present lecture it appears that this difficulty has been 

 overcome in Prof. Braun's system, as in Marconi's and Slaby's, 

 by the use of syntony, which has been utilised, not only to 

 separate different messages, but to augment the effect of the 

 waves received in any particular message. No actual result of 

 long distance trials is given in the report before us, but it is 

 natural to suppose that Prof. Braun's system will succeed in this 

 respect as have the other competing systems. It is interesting to 

 note that all experimenters have been led to this method of 

 separating messages ; when wireless telegraphy first attracted 

 attention it was suggested that messages might be confined to 

 their particular destination either by the use of reflectors or by 

 careful tuning of transmitter and receiver. Apparently only the 

 second of these has proved practical ; no doubt the long wave- 

 length of the vibrations used have proved fatal to the satisfac- 

 tory use of reflectors. 



The Board of Trade could not well have arrived at a more 

 satisfactory decision in the conference which was held last week 

 with reference to the proposal to reduce the charge for electric 

 lighting by putting a maximum limit of 6d., instead of 8^., per 

 unit in the provisional orders before Parliament this session. 

 The proposal, which emanated from the Board of Trade, was 

 supported by the London County Council but opposed by 

 several influential electrical bodies, including the Institution of 

 Electrical Engineers and the electrical section of the London 

 Chamber of Commerce, on the ground that it would have the 

 effect of discouraging electric lighting in small country places 

 where the population was scattered. It was urged by Colonel 

 Crompton, on behalf of the Institution of Electrical Engineers, 

 that the advantages to be gained by reducing the maximum in 

 every district would be outweighed by the disadvantage of pre- 

 venting the spread of electricity all over the country. This is, 

 however, no reason why the dwellers in towns should pay 

 highly that their brethren in the country may enjoy the benefit 

 of electric light, and the obvious solution is that the maximum 

 price should be regulated by the circumstances of the case. This 

 i? the .solution adopted by the Board ; they would fix, said Sir 

 Courtenay Boyle, a normal maximum of "jd. a unit, but in the 

 populous districts they would endeavour to make this 6d. ; in 

 special cases an %d. maximum would be allowed if the under- 

 takers were able to show sufficient cause. 



Several correspondents have written to us with reference to 

 falls of snow or ice crystals such as have been mentioned 

 already (pp. 420, 441). Prof. G. H. Bryan states that a fall of 

 snow stars occurred at Edgbaston, Birmingham, on January 6, 

 and a similar fall, in which the stars were somewhat larger, 

 happened at Bangor on February 15. " In the latter case," 

 he adds, "the crystals which fell in the morning were not 

 sufficient in number to form a coating on the ground, but many 

 of them remained unmelted during the afternoon in shady 

 corners. A few days later isolated stars were again falling, and 

 this time the rays were larger and more feathery." Dr. Abbot 

 noticed a fall of snow crystals at Tunbridge Wells in February, 

 and in connection with the subject he asks whether such crystals 

 should be considered as (i) skeleton crystals, (2) twins, or (3) 

 aggregates of very small hexagons. He remarks: — "What 

 seems to me the most interesting question is the regularity of 

 the angles and distances of the secondary branches ; and if we 

 are dealing with skeleton forms, are not ice crystals unique in 

 having these?" Another correspondent says that during a fall 

 NO. 1637, VOL. 63] 



of snow crystals at Newcastle at the end of January or beginning 

 of February last some of the crystals were about a quarter of 

 an inch in diameter, and the outline was nearly circular. 



Sir Courtenay Boyle objects, in the March number of 

 Macmillan' s Magazine, to many words in copimon use in 

 science. His objections are partly etymological and partly to 

 the vagueness of connotation of the words. Pliocene, miocene 

 and phonolite are incorrectly formed ; and the first two, to- 

 gether with palceozoic, mesozoic, kainozoic, Jurassic and triassic 

 are condemned because they are purely relative terms. Electron 

 is objected to because there is sometimes a doubt whether it 

 signifies a minute corpuscle having an electric charge or an 

 electric charge without the corpuscle. Kion and autokion are 

 suggested as preferable to the unsatisfactory words motor and 

 the hybrid automotor. 



The U.S. Monthly Weather Review for November, 1900 (the 

 last received) contains an interesting note of lightning from a 

 cloudless sky, by Mr. C. E. Ashcraft, jun., of the Weather 

 Bureau, Dominica. The phenomenon seems to be regarded in 

 the States as one of rare occurrence, but in the West Indies it is 

 frequently observed. The appearance of the flashes is that of 

 sheet-lightning, and they do not seem to be confined to any par- 

 ticular quarter of the sky. The author considers that the theory 

 of the exchange of electricities between vertical currents of air 

 is a plausible explanation, as the phenomenon has always been 

 observed in the evening, usually between seven and nine o'clock, 

 at which time the colder currents of air are descending and 

 setting up a vertical circulation, with steep gradients, and it is 

 also at this time that the maximum electrification of the air 

 occurs. Sometimes the sky is not absolutely clear, a few clouds 

 hanging over the mountains to the east of the station, but the 

 lightning will be seen far out to sea, where not the least vestige 

 of cloud is visible. The flashes have been observed more fre- 

 quently during the hurricane season. The phenomenon does 

 not appear to be peculiar to the region of Dominica alone, but 

 is said to have been observed in other parts of the tropics. 



A NOVEL marine torch, in which acetylene gas is the illumi- 

 nant, and of special design to ensure immediate ignition on being 

 plunged into water, is described in Fielden^s Magazine, The 

 torch, it is stated, " simply consists of a plain cyhnder of metal, 

 sizes varying from 3 to 8 inches in diameter and from i to 5 feet 

 in length. The cylinder, which is sealed at each end, contains in 

 a wire basket a quantity of carbide of calcium and it also contains 

 an air chamber to ensure sufficient buoyancy. At the head of 

 the cylinder a number of burners is arranged adjacent to which 

 is a small chamber containing calcium phosphide, which on 

 contact with water generates phosphuretted hydrogen, ignites 

 and also lights up the acetylene as it issues." The torch, which 

 has no mechanism, is automatic throughout, the only precaution 

 necessary before plunging into water being the removal of a 

 protecting strip of metal by pulling a ring. The illuminating 

 power of the torch can be gathered from the fact that a six -inch 

 torch burns from an hour to an hour and a half with a candle- 

 power of 2000 and a flame 12 inches high, and other torches 

 which are rechargeable will burn from half an hour to ten hours 

 according to size. 



A FEW interesting instances of the application of physical 

 instruments to the study of disease are given by Mr. Paget in a 

 short review of the chief events in medicine and surgery between 

 1800 and 1850, in the Middlesex Hospital Journal. The chief 

 influences which caused the great advance in the last ten years 

 of that half century are stated by him to have been, first, the 

 constant and general use of the microscope, both in physiology 

 and pathology. Men left off speaking of tumours as "strange 

 distempered masses" ; they set to work to learn their minute 



