6io 



NA TURE 



\_April 2^, 1886 



A CORRESPONDENT writes : — Under the name of the " phono- 

 phore " a remarkable telephonic invention is about to be intro- 

 duced to public notice by Mr. Langdon Davies. The name is 

 given to a contrivance which, while absolutely a non-conductor of 

 continuous electric currents, still allows of the passage or transmis- 

 sion of rapidly-alternating currents such as correspond to sounds 

 in vocal and harmonic telephony. The "phonophore" itself 

 may be regarded as at once a condenser and an induction coil. 

 It consists essentially of two insulated wires laid side by side, 

 twisted together and wound up upon a bobbin, one end of ?ach 

 wire being completely insulated. Regarded as a condenser, its 

 capacity is very feeble indeed. Regarded as an induction coil, 

 it will be seen that neither the primary nor the secondary forms 

 a closed circuit. Yet it transmits telephonic speech perfectly. 

 It follows that Mr. Langdon Davies has solved the problem of tele- 

 phoning on an open 'circuit. But the real object of the invention is 

 to enable telephonic messages, including both vocal and harmonic 

 under that name, to be transmitted through the ordinary tele- 

 graph-wires without interference with or from the telegraphic 

 messages that are simultaneously passing through the wires. For 

 many months Mr. Langdon Davies has been at work experi- 

 menting upon the lines of telegraph-wire running across the 

 county of Kent. He has devised a whole series of new tele- 

 phonic apparatus in which not only the induction-coils of the 

 transmitters, but also the bobbins of the receivers, are replaced 

 by open-circuit phonophore coils. Apart from its purely technical 

 value, the new instrument presents several points of great scien- 

 tific interest, and opens up sundry new problems to the mathe- 

 matical physicist. 



A NEW method of reading small angular deflections, as, for 

 example, those of galvanometers, has been devised by Dr. 

 D'Arsonval. It may be briefly described as the inverse of 

 Poggendorff's (subjective) method. Usually the objective of 

 the observing telescope forms at the conjugate focus a diminished 

 image of the object — the scale as reflected in the mirror. Dr. 

 1 /Arsonval places the scale — a small one, reduced by pho- 

 tography, giving tenths and twentieths of a millimetre — at this 

 conjugate focus, and obtains a magnified image of it reflected in 

 the mirror, and situated above the objective. This enlarged 

 image, which is enormously displaced for small angular move- 

 ments of the mirror, is again observed by an eyepiece bearing 

 the usual cross-wires. 



The annual meeting of the Iron and Steel Institute has been 

 arranged to take place in London on the 12th, 13th, and 14th of 

 May next. On the first day of the meeting the President (Dr. 

 Percy, F. R. S.) will deliver an opening address. The Council 

 have decided to present the Bessemer Gold Medal to Mr. 

 Edward Williams, of Middlesbrough, who was for many 

 years connected with the Dowlais Company, and Bolckow, 

 Vaughan, and Company, in recognition of his services to 

 the Institute and to the iron trade generally. The pro- 

 gramme embraces a list of fifteen papers, four of which are 

 adjourned from the meeting held in Glasgow last autumn, while 

 eleven are entirely new papers. The subjects dealt with 

 include the manufacture of tin plates (which is still, in spite 

 of recent efforts of the Germans and Americans to secure a 

 portion of the trade, an almost exclusively English industry) ; 

 American blast-furnace practice ; the tenacity of steel wire ; the 

 cost of blow-holes in open-hearth steel, by which the strength 

 and reliability of that metal is affected ; a neutral lining for 

 metallurgical furnaces ; the composition of cast iron; the use of 

 wrought-iron conduit pipes ; the manufacture of chrome steel ; 

 the endurance of steel rails ; the microscopical structure of steel ; 

 and certain descriptions of Indian castings. 



The Institution of Mechanical Engineers will hold its next 

 general meeting on Thursday, May 6, at 7.33 p.m., and Friday, 



May 7, at 3 p.m., at the Institution of Civil Engineers, 25, 

 Great George Street, Westminster. The papers to be read are : 

 "On the Distribution of the Wheel Load in Cycles," by Mr. 

 J. Alfred Griffiths, of Coventry ; " On the Raising of the 

 Wrecked Steamship Pur of the Realm" by Mr. Thomas W. 

 Wailes, of Cardiff; "On Refrigerating and Ice-Making Ma- 

 chinery and Appliances," by Mr. T. B. Lightfoot, of London ; 

 " Notes on the Pumping-Engines at the Lincoln Water- Works," 

 by Mr. Henry Teague, of Lincoln. 



Mr. Cuthbert E. Peek's Second Report of the Meteoro- 

 logical Observatory he established at Rousdon, Devon, in the 

 end of 18S3, has reached us, and it shows in several respects an 

 improvement on the First Report. The weather notes of the 

 months, while retaining their popular character, are now fuller 

 and more precise, and form, so far as can be expected from the 

 records of a single station, a very serviceable account of the 

 weather of the year. A comparison of the weather forecasts of 

 the Meteorological Office with the actual weather experienced at 

 Rousdon continues to form part of the regular work, with the 

 result that for 18S5 the reliable forecasts for this part of England 

 were 11 per cent, above that of 1884. Some interesting observa- 

 tions are made regarding sea-fogs and their extension inland, for 

 observing which, the Rousdon Observatory is «ell situated. A 

 useful table is added to the Report in which the months are 

 grouped respectively in order of frequency of sea-fogs, of mean 

 wind velocity, of duration of bright sunshine, of rainfall, and of 

 temperature ; and we are glad to see that the mean temperatures 

 of the months are included in the Report. We still, however, 

 desiderate the monthly means for atmospheric pressure and 

 humidity, and certain other details, which, as they are indis- 

 pensable to such publications, Mr. Peek will, no iloubt, include 

 in future issues of his reports. 



Those interested in the Daily Weather Reports of the 

 Meteorological Office will have noticed with satisfaction the 

 addition, since April 7, of a paragraph headed "Continental 

 Information," which details the general features of the weather 

 over the Continent on the previous day, taken from the data of 

 the Daily Continental Weather Reports. With this greatly 

 extended field of observation, not only is the weather of Europe 

 generally brought more or less vividly before us, but a much 

 clearer explanation is afforded of the more important weather 

 changes occurring in the British Islands than can be given by 

 weather maps covering a more restricted area. It is evident 

 that much assistance would be rendered in framing forecasts of 

 weather if daily telegrams were received from additional Con- 

 tinental stations. The immense importance of this extension 

 will be seen by a reference to the recent anticyclonic areas of 

 high pressure over Russia, often extending westwards through 

 Scandinavia to the north of the British Islands, in connection 

 with the low pressures at the time over southern and south- 

 western Europe, as the immediate cause of the past hard winter 

 (see Nature, vol. xxxiii. pp. 447-48). Good results may fairly 

 be expected to follow, as the area embraced by the stations 

 increases in extent and in height through the atmosphere. 



A correspondent points out that the meteorological station 

 at Sonnenblick, near Salzburg, 10, 170 feet high, is not the highest 

 in the world, that on Pike's Peak, Colorado, U.S., being 14,134 

 feet high. 



The various elevated meteorological stations of Europe, with 

 their respective heights in metres, are thus given by Dr. Breiten- 

 lohner, the Director of the Observatory at Sonnenblick, near 

 Salzburg, in an article in the last number of the Mitt/ieilungen 

 of the Vienna Geographical Society : — Italy — Monte Cimone, 

 Apennines, 2162 ; Etna, Sicily, 2900. France— Puy-de-D6me, 

 Auvergne, 1463 ; Pic de I'Aignal, Cevennes, 1567 ; Mont Ven- 

 toux, Cottian Alps, i960 ; Pic du Midi, Central Pyrenees, 



