June 5, 1913] 



NATURE 



159 



political economy, generally to the entire neglect of 

 the more exact departments of science, and, above 

 all, he prefers votes to history, political economy , 

 science, or anything else. The instincts of the man of 

 exact science are indeed opposed to those of the 

 normal party politician. The man of science must be 

 very sure of his grounds before he makes a state- 

 ment, and must rigidly compare all existing facts 

 with any theory before he declares the probability, or 

 his personal conviction, of its truth. Above all, he 

 must be careful to avoid the influence of preconceived 

 views of his own or the views of his friends before 

 he draws his inferences from observed facts. Where 

 would the party politician be if he based his action 

 on such grounds? He would soon be hounded out 

 of his party, or reduced to slavish submission by the 

 party whip. 



So long as we have party government I fear there 

 is no escape from the predicament. The object of 

 the Science Guild is to provide some partial remedy 

 at least for this undesirable state of affairs. 



When Ministers have on any particular subject re- 

 cognised the need of scientific advice they always 

 have the Royal Society to which they may apply, and 

 from that society they can always obtain sound advice 

 on any subject that involves exact science. But it 

 needs some scientific knowledge to know when sound 

 scientific advice is required ; and too often Govern- 

 ments do not know when they should ask for such 

 advice, or they may know enough to realise that 

 acceptance of the advice they require might involve 

 expenditure that would not purchase votes or might 

 lead to action that would be unpopular with some of 

 their constituents. 



Now it is here that a body like the Science Guild 

 may rightly and does most rightly and properly come 

 in. Unlike the Royal Society, it does not wait to be 

 consulted. As a non-political body, it desires no party 

 advantage from its action. Therefore when a Bill is 

 in course of preparation or discussion in which it is 

 clear that scientific advice has been neglected or not 

 demanded, the Science Guild refers the matter to a 

 competent committee of its own, and tenders advice 

 without solicitation. It does not stump the country 

 to proclaim its views ; it leaves to the Government or 

 the member who fathers the Bill the responsibility 

 of adoption or non-adoption of its advice ; it leaves 

 to others to use any further pressure that may be 

 required, based upon the views of the Science Guild. 



Our guild is yet young, and it takes time before 

 the elector at large can realise the due weight of its 

 views. But no one can question the competence of its 

 committees ; the men who compose them are well 

 known for their scientific standing and sound prac- 

 tical common sense ; and, as time goes on, Govern- 

 ments will more and more find the importance of 

 listening to the advice so tendered. No man was 

 more sensible of this than was Lord Haldane, who has 

 been our president since the formation of the guild 

 nearly seven years ago. It is with much regret we 

 learn that the pressing duties of his high office have 

 compelled Lord Haldane to resign the presidency of 

 the guild. We are most grateful to him for the ser- 

 vices he has rendered, and for the recognition he has 

 given to the value of the work aimed at and done 

 by the guild. 



We all, I am sure, are gratified to know that the 

 Rt. Hon. Sir William Mather has consented to fill 

 the chair vacated by Lord Haldane's retirement. He, 

 as we all know, has taken a prominent part in the pro- 

 motion of technical education throughout the country. 

 He has been an able and active member of the guild, 

 and we all have confidence that in his hands and 

 under his inspiring influence the work of the Science 

 Guild will grow and nourish. 

 NO. 22 75, VOL. qi] 



JOINT MEETING OF BRITISH AND 

 FRENC II ELE( 'TR1CAL ENGINEERS. 



DURING the joint meeting of the British and 

 French Electrical Engineering Institutions, held 

 in Paris on May 21-24, a wide range of subjects was 

 discussed. The greater part of the time was devoted 

 to electric railway traction. The electrical equipment 

 of purely urban and suburban railways has ahead) 

 become almost a mere question of economics and 

 technical detail ; the broader engineering and scien- 

 tific problems are solved. So far, however, the re- 

 placement of the steam train by the electric train on 

 main lines has only been limited, and this is a work 

 for which the electrical engineer is making ready. 

 Its consideration cannot be deferred until the improve- 

 ments in the economy of generating and distributing- 

 electrical energy, and converting it into mechanical 

 energy on the train, are such that there can be no 

 other reasonable method than to burn the coal at 

 the pit's mouth instead of the locomotive furnace ; for 

 in the meantime the "electrification" of suburban 

 lines must continue, and the railway engineers natur- 

 ally desire to equip their lines on some system which 

 will lend itself to main line traffic as well as sub- 

 urban, without extensive alterations being necessary 

 when the second part of the problem is taken in hand. 

 For this reason, the presentation and discussion of six 

 papers on electric railways by French electrical 

 engineers of high repute was particularly well timed. 



The chief reason for different methods in dealing 

 with urban railways pure and simple and main line 

 railways may be summed up in two words, viz. dis- 

 tance and locomotives. On an urban or suburban 

 line, the energy required is spread over a compara- 

 tively small geographical area; while on a main line 

 the energy has to be transmitted over a considerable 

 distance. Again, the traffic on an urban or suburban 

 line is mainly passenger traffic, while a large propor- 

 tion of the traffic on a main line is for the conveyance 

 of goods. 



In the majority of suburban lines a comparatively- 

 low electrical pressure (500 or 600 volts) is carried on 

 the conductor along the track; this means a propor- 

 tionately large current is required, but the voltage- 

 drop and loss of energv which this entails are not 

 serious on account o'f the small distance be- 

 tween the power station or substation and the train. 

 Partly to facilitate the conveyance of this high cur- 

 rent from the conductor rail to the train, and partly 

 to enable trains to be conveniently subdivisible into 

 lengths corresponding with the density of traffic at 

 various periods of the day, the " multiple-unit " system 

 is employed, in which there are two or more motor- 

 coaches on each train, each taking current from the 

 " live " rail conductor, but all controlled from the 

 cab of the front motor-coach. _ _ 



On long main lines, on the other hand, it is 

 obviously more economical to transmit the energy to 

 the train in the form of a higher potential and lower 

 current, and this is the more desirable owing to the 

 necessity of using locomotives, at all events for the 

 goods traffic, which entail transmission of the whole of 

 The current to the train at one point or one set of con- 

 tacts with the live conductor. Therefore, other things 

 being equal, a high-pressure single-phase current, as 

 is being- used on the London, Brighton and South 

 Coast Railway, and also to some extent on the Mid- 

 land Railway, and on several American and German 

 lines, is indicated as the solution to the problem so 

 far as main line traffic only is concerned; it is easy 

 to generate and transmit, and requires onlv one live 

 conductor, which is overhead. On the other hand, 

 the overhead work introduces complications and ex- 

 pense for suburban traffic in which there are many 



