June 27, 1907] 



NA TURE 



209 



he said, could be passed by men who have not that 

 acquaintance with scientific principles which is desirable.. 

 The papers have often been so stereotyped that corre- 

 spondence and other methods of cramming only arc needed 

 to enable a man to pass. The composition of the board 

 of examiners had often been characterised by conspicuous 

 absence of men qualified b}' scientific training and know- 

 ledge to examine candidates, however eminent might bo 

 their position in particular branches of the mining pro- 

 fession. Mr. Rowley emphasised his opinion that a solid 

 foundation of a broad and liberal education was essential 

 to the student prior to his course in applied science. 



Scilioii v.. Shipbuilding. Chairman, Dr. F. Elgar, 

 F.R..S. 



.A joint discussion with Section II. on harbour and dock 

 requirements opened the work of this section. A very 

 important discussion on the uses of high-tensile steel was 

 opened by three papers contributed by Mr. .'\. E. Seaton, 

 Mr. A. F. Yarrow, and Mr. E. W'. De Rusett. High- 

 tensile steel for structural work may be described as steel 

 having an ultimate tensile strength of about 40 tons per 

 square inch. In the Forth Bridge such steel was used in 

 compression only ; Mr. Seaton was of the opinion that 

 to-day there need be no hesitation in using it under tension. 

 By use of this material it Is possible to reduce largely the 

 weight of a given structure. Recently the huge Cunard 

 ships have been constructed so as to withstand the heavy 

 expected stresses by the free use of the high-tensile steel 

 of Spencer and Colyillc. Mr. Yarrow quoted the present 

 Admiralty practice of steel of 37 Ions to 43 tons per 

 square inch with specified minimum elongations in 

 S inches. In his own practice a considerable reduction of 

 dead weight had been effected by the use of high-tensile 

 steel. Mr. E. W. De Rusett gave information as to the 

 use of high-tensile steel in the construction of the 

 Matirelania. By instruction of the authorities of Lloyd's 

 Registry, rivets of mild Ingot steel were adopted. The 

 rivet holes in plates less than J inch thick were punched 

 i inch under size and riniered out. This method was 

 found not to interfere with the strength of the joints. 

 Rivet holes in plates more than J inch thick were drilled. 

 Sir \Vm. White recommended for the proper use of high- 

 tensile ,^teel (a) thorough testing in the makers' works ; 

 (h) proper treatment of the material (as regards heating, 

 &c.) in the shipbuilders' yards : (c) structural arrangements 

 suitable for the new material. He was of the opinion 

 that both mild steel and high-tensile steel can be success- 

 fully used in the same structure. Rivets of quality agree- 

 ing with the material of the plates should be employed, 

 and such was the practice of the Admiralty. Sir P. Watts 

 said that high-tensile steel rivets were at present used 

 successfully in the Service. Mr. Colville gave the results 

 of the experience of the Steel Co. of Scotland on the 

 manufacture of high-tensile steel. Mr. Ritchie, of Park- 

 head F'orge, quoted the case of a steam boiler of high- 

 tensile steel working at 500 lb. per square inch pressure. 

 Mr. Thearle, of Lloyd's, spoke of the necessity for avoid- 

 ing improper heat treatment of high-tensile steel rivets. 

 Other subjects dealt with in this section were structural 

 details of cargo steamers, arrangements for working cargo, 

 high-speed vessels, modern applications of superheating, 

 and the welding of structural materials in place. In the 

 last, methods of electric welding, welding by the oxy- 

 hydrogen and oxyacetylene flames, and welding by the 

 use of thermit were discussed. 



Section VI., Waterworks, Sewerage, and Gasworks. 

 Cliairman, Sir George Thomas Livesey. 



The first paper read in this section was on the com- 

 parative cost of pumping by steam, internal combustion 

 engines, and electricity, based on actual working. The 

 authors, Messrs. Charles Hawksley and Henry Davey, 

 made out a strong case In favour of direct pumping by 

 steam engines. Speakers in the discussion disagreed with 

 certain figures given in the paper. Thus the authors give 

 I lb. of oil per B.H.P. generally for oil engines, but the 

 Diesel oil engine has a guaranteed consumption of 04 lb. 

 of oil per B.H.P. ; 1-75" lb. of coal per B.H.P. for gas 

 engines is stated in the paper to be the engine-maker's 

 estimate, but 1-25 lb. would be nearer. Electric current 

 could also be obtained at a cheaper rate than that given, 

 viz. hd. per unit. 



Papers on water softening and water hardening were 

 contributed by Messrs. W. Matthews and J. Watson re- 

 spectively. Softening is of value in many cases where the 

 water is too hard to be available for supply, and the 

 process also gives a means of defence against bacteria. 

 The working in practice of various systems of water 

 softening was discussed. The practice of hardening water 

 for domestic purposes is intended to counteract acidity 

 and neutralise peaty water possessed of lead-dissolving 

 properties. 



Applications of towns' gas as a heating agent were de- 

 scribed in a paper by Mr. W. H. Y. Webber. The author 

 referred to the practice now generally adopted by gas 

 engineers of speaking of their product in terms of its 

 calorific value rather than of its illuminating power. The 

 domestic uses of gas for heating purposes were dealt with, 

 and the author expressed his opinion that producer gas 

 did not make headway against town gas at 2S. per 1000 

 cubic feet. 



The distribution of gas at increased pressure was intro- 

 duced by Mr. C. C. Carpenter, who described the present 

 practice of the South Metropolitan Gas Company in using 

 non-positive blowers giving an initial pressure of about 

 20 incheJ of water. Gas engines are preferred for driving 

 the blowers as being more convenient. This company 

 has 1200 miles of pipes, and finds that the unaccounted 

 gas amounts to 4! per cent. only. 



Mr. J. D. Watson contributed a paper on sewage 

 disposal by biological processes. In which he gave the 

 results of the methods adopted at Birmingham, where 

 sewage purification is effected by mechanical precipitation 

 and septic treatment. 



The relative merits of chemically treated, settled, and 

 septic sewage in preparing the liquid for oxidising beds 

 formed the subject of a paper by Mr. G. A. Hart. The 

 author has compiled facts obtained from observations 

 made on the sewage of Leeds during the last nine years. 

 The most effective chemical precipitant was found to be 

 a combination of 6 to 8 grains of lime and 2 grains of 

 aluminium sulphate per gallon of sewage. Settlement is 

 employed sulticient to reduce the suspended solids in crude 

 sewage to an average of about 8 grains per gallon. Deal- 

 ing with septic fermentation, the author stated that at a 

 twenty-four hours' rate of flow about 30 per cent, of the 

 suspended solids were digested in the tanks, 31 per cent, 

 passed out with the eflluent, and the balance of 39 per 

 cent, remained as deposit. 



Section VII.. .ipplicalions of Electricity. Chairman, 

 Colonel R. E. B. Crompton, C.B. 



The first paper taken was on electrical transmission 

 gears on motor vehicles, by Mr. A. A. C. Swinton. The 

 author directed attention to the crude methods of gear 

 changing used in petrol-driven motor vehicles, and gave 

 short descriptions of several arrangements of electrical 

 transmission which have been adopted. Mr. Hart gave 

 the results of his experiments using continuous current 

 machinery, which he had discarded in favour of polyphase 

 alternating current. He had now an omnibus running in 

 which the consumption of petrol amounted to one gallon 

 per 65 miles, the electric machinery being used for start- 

 ing only, giving a smooth and rapid acceleration. Mr. 

 W. H. Stevens advocated the use of continuous current. 

 Mr. Swinton referred to the question of the weight of the 

 petrol-electric equipment, which is greater than that of 

 purely petrol machinery. 



The subject of electric working of railway points and 

 signals was opened by Mr. Ferreira, who enumerated the 

 principal conditions considered essential in modern signal- 

 ling, and discussed the various electric methods adopted 

 for complying with these conditions. 



Papers on upkeep charges on large electric generating 

 sets and on modern applications of electricity to mines 

 were contributed by Messrs. Burstall, Highfield and 

 Sparks. In the last paper the application of the high-lift 

 centrifugal pump in combination with the electric motor 

 was mentioned as showing a great advance on previous 

 methods of pumping. 



On the evening before the formal opening of the con- 

 ference, the James Forrest lecture, on " Unsolved Problems 

 in the Design and Prooulslon of Ships," was delivered bv 

 Dr. Francis Elgar, F.R.S. 



NO. 1965, VOL. 76] 



