500 



NA TURE 



[September 13, 1906 



gives the results of his observations of Phoebe, the ninth 

 satellite of Saturn, made with the 40-inch on July 24 

 and 29. The satellite was about im. in R.A. and 6' in 

 declination from the planet, and had a magnitude of 16-5 ; 

 at times it appeared hazy. The observations give the 

 following corrections, taken (observed-calculated), to Dr. 

 Ross's ephemeris : — 



July 24 

 29 



'O 0-93 

 -0 0-87 



+ 35 

 + 02-9 



ENGINEERING AT THE BRITISH 

 ASSOCIATION. 

 T N his presidential address to the section. Dr. Ewing 

 dealt with certain aspects of the inner structure of 

 iiittals and the manner in which they yield under strain, 

 and he made a notable departure from the usual custom 

 of such addresses by illustrating his speculations by experi- 

 ments and by models in order to demonstrate his ideas as 

 to the processes of crystal building. 



.\fter the presidential address a paper vifas read by 

 Major W. E. Edwards, R.A., on modern armour and its 

 attack. The author first gave a very complete and useful 

 history of the application of armour to ships and forts, 

 and then explained in detail the elaborate and costly pro- 

 cesses through which the material passes, from the casting 

 of the steel ingot to the completion of the plate. The 

 second part of the paper dealt with the attack of armour 

 and the various ways in which a plate may yield, and the 

 influence of the cap in reducing the resisting power of 

 hard-faced plates. In the discussion Sir William White 

 I'xpressed the opinion that British armour-plate makers had 

 introduced many of the more important improvements in 

 the resisting power of armour-plates, and that eventually 

 the 6-inch gun would be chiefly used for defence against 

 torpedo craft. 



The first paper on Friday, August 3, was on the removal 

 of dust and smoke from chimney gases, by Messrs. S. H. 

 Davies and F. G. Fryer. The paper dealt with an ingenious 

 plant the authors have designed and fitted up at the 

 cocoa works of Messrs. Rowntree and Co. for thoroughly 

 washing the smoke, and for removing from it the whole 

 of the grit and dust and practically all the sulphur acids. 

 Members of the section had an opportunity later on of 

 seeing this plant in operation ; it certainly thoroughly 

 effects the purposes for which it was installed, and it 

 might certainly be adopted with advantage in many 

 factories where a cheap and plentiful supply of water is 

 available. 



In the next paper, on standardisation in British engineer- 

 ing practice. Sir John Wolfe-Barry gave an account of 

 the admirable work which has been carried out by the 

 Engineering Standards Committee since its first institution 

 in iqoi at the instance of Sir John Wolfe-Barry himself. 

 There are now thirty-six subcommittees with 260 members 

 dealing with some thirty different branches of the work. 

 The work of the committee has been invaluable both to 

 manufacturers and to engineers, and the publications of 

 the committee are indispensable to all engineers. 



Dr. Ewing has during recent years done much valuable 

 research work on the crystalline structure of metals, both 

 in a strained and in an unstrained state, and it was only 

 natural that there should be several papers on this 

 important branch of the subject of the strength of 

 materials. Mr. W. Rosenhain dealt with the deformation 

 and fracture of iron and steel, and his paper was illus- 

 trated by a number of beautiful lantern slides. The author 

 of this paper has done such admirable work in the micro- 

 scopic study of the crystalline structure of metals that 

 everything he has to say on this subject is sure to be of 

 value. In his latest researches he has by a most ingenious 

 method been able to study the crystalline structure of the 

 actual fracture itself in broken test-pieces. The second 

 paper on this subject of the crystalline structure of metals 

 was by Mr. J. E. Stead, and dealt with segregation in 

 steel ingots and its effect in modifying the mechanical 

 properties of steel. To all those concerned either with the 

 manufacture or with the employment of steel in industrial 

 operations this paper was most valuable, for the author 



NO. 19 24, VOL. 74] 



had brought together a large amount of information 

 previously scattered in the pages of various publications. 

 I'he microscopic study of the crystalline structure of 

 different portions of steel ingots is rapidly changing the 

 views of engineers in regard to many important problems 

 in connection with the life of steel rails, and there is no 

 question that the microscope now plays as important a 

 part in the laboratory of the metallurgist as in that of the 

 biologist. 



Dr. H. C. H. Carpenter next read his paper on struc- 

 tural changes in nickel wire at high temperatures ; this 

 research, carried out at the National Physical Laboratory, 

 was intended to throw light on the fact that fundamental 

 changes occur in the mechanical properties of nickel wire 

 used as the heating coil of an electrically-heated porcelain 

 tube-furnace. Here again the microscope was the chief 

 instrument in the research, and the study of the crystalline 

 structure of the wires showed, the author suggested, that 

 wire intended for electrical heating should be as free from 

 gases as possible. A paper by Mr. W. Taylor describing 

 a magnetic indicator of temperature for hardening steel 

 concluded the day's proceedings. 



On Saturday, August 4, the section paid a visit of in- 

 spection to the Roundhills Reservoir of the Harrogate 

 Corporation. The dam, a masonry one, will, when com- 

 pleted, be 125 feet in height above tiie river bed, and 

 members of the section were fortunate enough to see the 

 work when the more difficult operations of such an under- 

 taking were just in their most interesting condition. 



On Monday, August 6, the first paper read was by Prof. 

 Hudson Beare, on the new engineering laboratories of the 

 University of Edinburgh and their equipment ; the author 

 pointed out that he had made special provision in these new 

 laboratories for experimental work of an advanced character 

 on the strength of materials and on hydraulics. At the con- 

 clusion of the discussion of this paper Sir W. H. Preece read 

 a communication on glow lamps up to date, and the grading 

 of voltages, in which he strongly advocated that steps 

 should be taken to secure uniformity of practice in regard 

 to regulation of voltage in connection with the distribution 

 of electrical energy, and also in regard to the grading of 

 carbon filament glow lamps ; in the latter part of the 

 paper data were given to show how poor in quality were 

 many of the lamps on the English market. In the dis- 

 cussion on this paper Colonel Crompton directed attention 

 to the fact that only a comparatively small proportion of 

 lamps was used in private houses in America, while in 

 this country the proportion was large ; he also pointed out 

 that the demand for electric current for power and for 

 heating was now becoming a very important factor in the 

 working of central stations. 



In a paper on the advent of single-phase electric trac- 

 tion, Mr. C. F. Jenkin directed attention to the rapid 

 advance of electric traction on railways, and pointed out 

 its advantages. He pointed out that the real advantage 

 of electrification was that it would make the line pay 

 better. Mr. Jenkin then dealt with the two alternative 

 systems — alternating current transmission, continuous 

 current distribution with low-tension third rail, and alter- 

 nating current transmission with high-tension trolley wire : 

 he was of opinion that the latter method had very great 

 advantages, and he advocated also single-phase instead of 

 three-phase currents. 



The business of the section for this day concluded with 

 a paper by Mr. A. J. Martin on a general supply of gas 

 for light, heat, and power production. Mr. Martin pointed 

 out that the main obstacle to the general use of gas for 

 purposes other than lighting was its cost, and that the 

 chief causes of this high cost were the standards of illumin- 

 ating value to which gas has to conform and the high 

 prices paid for coal. At the present day both natural gas 

 and coal gas have been piped in America to great distances 

 (in the case- of natural gas to 200 miles) with success, and 

 Mr. Martin was of opinion that it would be perfectly 

 feasible to generate gas cheaply at large works in the 

 centre of our coalfields, and then to convey it under 

 pressure to all our large cities for manufacturing and heat- 

 ing purposes. 



In the course of the afternoon many members of the 

 section took part in an excursion to Middlesbrough to visit 



