May 4, 191 1] 



NATURE 



335 



number of trains, and t±ie curve of the rise in the number 

 of trains is shown on the diagram ; but the really 

 significant feature is the rise in the number of passengers 

 carried, 35,000,000 — 72,000,000, which is the direct result 

 of the increased facility in travelling. Now it is in such 

 a case that the importance of the signalling and braking 

 come to be almost pre-eminent, quite apart from the mere 

 mechanical problem. 



1 may point out that the District Railway, in common 

 with most other electric railways of this country, has 

 what is known as a " track system of signalling," which, 

 apart from the fact that the driver holds what is known 

 as " the dead man's handle," which upon being released 

 causes the train to stop, the train independently stops itself 

 upon coming to a portion of the line not cleared by the 

 previous train. 



I have given you some examples that this country is 

 not so far behind as we are so often told ; and we have 

 another in the fact that the District Railway has created 

 a most beautiful system, by which the signalman is now 

 absolutely independent of fog or darkness ; he can see every 

 train, or rather its picture, as it moves along the track in 

 an illuminated diagram in front of him. No one could 

 watch, as I have had the privilege of doing, the operation 

 of this system in a signal-box without feeling certain that 

 it must become universal in a very short time. You may 

 like to see an actual panel from a signal-box and a view 

 of what the interior is like with the signalman operating, 

 instead of cumbrous levers, only a few small handles. 



With regard to the question of vibration and oscillation, 

 these are gradually being diminished as machinery is per- 

 fected, and you will see from the model illustration that 



Fig. 6. — Progress in Atlantic Stiamers (Cunard). 



y are important, and may become very serious. They 

 liave, for instance, given Mr. Brennan much trouble in 

 perfecting his wonderful mono-rail, with which we shall 

 yet perhaps see every record broken ; and you will re- 

 member Mr. Parsons' statement in this hall a week or 

 two ago that an ounce out of balance on the Laval 

 turbine represents an actual pull at the axle of no less 

 than a ton. 



There are many other features which I have not time 

 to enter into. There is one, however, which I will briefly 

 touch upon, as it is the secret of our safe railway travel- 

 ling. I will illustrate the matter by an experiment in 

 which a pair of wheels connected by an axle keyed firmly 

 to both are made to run along a pair of rails. You will 

 notice that the wheels are " coned " instead of having 

 .lindrical rims, and it is easy to see that any movement 

 i' ways is at once corrected automatically, and within 

 rtain limits no rim at all is required for the flanges in 

 order to keep the wheels upon the rails. The same model 

 illustrates the important property of " super-elevation " 

 applied to the outer rail of a curve. You will see, with 

 proper super-elevation, the wheels run safely round this 

 sharp curve even at a high speed. Time does not permit 

 me to onter at any length on the question of development 

 of power or the nature of resistance to motion. I will 

 content myself with saying that, with regard to the former, 

 we have already seen that the power of flight has been 



NO. 2166, VOL. 86] 



made possible by the invention of the small high-power 

 internal-combustion engine, and it is to the same invention 

 that the marvellous speeds obtained with small boats is 

 due. We can scarcely realise what will be the result when 

 the internal-combustion engine has been developed further 

 for the purpose of locomotion. Our prospects of a further 

 great advance in speed record-breaking appears to lie in 

 this direction, and we already hear of a new car of 250 

 horse-power with which a speed of 140 miles per hour is 

 confidently expected. 



On water, as on land, our actual speed of travelling falls 

 far below maximum speed records, and we do not com- 

 mercially travel at much more than half the possible 

 speed, as you see from Fig. 3, where the speed of the 

 Mauretania is shown graphically. Fig. 6 is a chart of 

 the progress of Atlantic shipping, taking the Cunard line 

 as an example, and these curves indicate that the rate of 

 increase of horse-power and tonnage is rising far faster 

 than the rate of speed, and indicates how relatively highly 

 the rate of power has increased for the gain of speed. 



We have now passed briefly in review the nature of the 

 problems which confront us in our con- 

 tinuous efforts to increase the safe and 

 ^'* practical speeds of mechanical loco- 

 motion. We see that at the root of it 

 all lies the question of artificial power 

 and the harnessing in compact and con- 

 venient form the stored-up sources of 

 energy in nature in order to overcome 

 the opposing resistance, and we can 

 realise that, although we have obviously 

 reached the limits of animal loco- 

 motion, we are far from having reached 

 any limitation in regard to the speed 

 of self-propelled machines. We see 

 that in all three forms of locomotion, 

 earth, air, and water, the advance has 

 been far more rapid during the last 

 ot^ f^w years than ever before, and we can 

 realise that there is yet a considerable 

 margin by which speed of travelling 

 could be increased as the demand for it 

 is made ; and nothing is more certain 

 than that the demand will be made. 



I began my lecture by pointing out 

 why speed was instinctively taken as a 

 test and a measure of locomotion from 

 the earliest times. Shakespeare makes 

 !one of his characters say, " The spirit 

 of the time shall teach me speed," but 

 he might have said this of any period 

 equally with that of King John, though 

 never more so than of to-day, for the changes in 

 the requirements of civilisation have only altered 

 in detail, and speed is of as much importance 

 as ever in the struggle of life. The probably un- 

 conscious recognition of this fact has always led ques- 

 tion of speed to be raised as prime factors in proposals 

 for new modes of locomotion, and it is interesting to look 

 back only a comparatively few years to see, in raising 

 these views, this was always the case, but how little any 

 ideas of future possibilities were realised. When George 

 Stevenson, backed up by a few courageous and enter- 

 prising men, was fighting the battle of the railway, and in 

 particular trying to secure the passing of the Bill for 

 improved communication between Liverpool and Man- 

 chester, the question of speed was the most important one 

 raised ; the opposing counsel, Mr. Harrison, spoke as 

 follows : — " When we set out with the original prospectus, 

 we were to gallop, I know not at what rate ; I believe it 

 was at the rate of 12 miles an hour. My learned friend, 

 Mr. Adam, contemplated — possibly alluding to Ireland — 

 that some of the Irish members would arrive in the 

 waggons to a division. My learned friend says that they 

 would go at the rate of 12 miles an hour (with the aid 

 of the devil in the form of a locomotive, sitting as postilion 

 on the fore horse, and an honourable member sitting 

 behind him to stir up the fire, and keep it at full speed. 

 But the speed at which these locomotive engines are to 



