NATURE 



[May 4. 



'HI 



(<roun(l, >ti>|>» loi .1 iiiuiiu lit jll^t ^l^ much at in the 

 lorwiinl poitiiion nl>ovc m«nti<irn<l, and if you wutch a 

 dof; );all(i|>iii^ you cnn sec qui(<- clearly the rollini; utrukc 

 actiun I hav«> nicntiotu'd. 



\Mth the at>ov<- factii in mind, we ran undemtand cxartly 

 tlw limitations to animal locomotion. In the words of 

 Mr. Muybridge : — " When the bo<ly of an animal is Ix-injj 

 nirri'-cl forward with uniform motion, the limbs in thi-ir 

 cliiiuM to it have alternately a pro(;r<SHive and a retro- 

 ^11 ssivf action, their various portions acc^leratinjj in rom- 

 parutivt' speed and repose as they extend downwards to th«' 

 feet, which are subjected to successive chanjjes from a 

 condition of absolute rest, to a varying increased velocity 

 in comparison with that of the body." Hence all animal 

 locomotion absolutely lack* that continuity of movcnifnt, 

 the pnxluction of which we shall see is the distinguishing; 

 feature and the direct cause of the hifjh speeds attained in 

 mechanical locomotion. 



'Ihe e.xchanjje of the intermittent 

 inoviiiient of nature for one havinj^ the 

 <I-Niri(i continuity of movement has 

 bti I) elTecteil by means of what is 

 pt>ssibly the greatest and yet the 

 simplest of all human inventions, 

 namely, the wheel. 'I'he wheel was 

 made and used probably thousands of 

 years before man learnt to replace 

 muscular efTort by that of steam and 

 the other forces of nature, the origin 

 of the wheel being absolutely lost in 

 antiqi^ity. 



From the models which I now show 

 will be noticed the way in which the 

 wheel acts and how it overcomes the 

 defect of animal locomotion, giving a 

 rotary and continuous movement in- 

 -stead of a reciprocating and variable 

 one. At one and the same time the 

 wheel, therefore, does away with the « 

 three causes of loss shown i.i the § 

 diagram as occurring with animal loco- ' 

 motion. The mere use of the wheel 5 

 has enabled man himself, by his own *■ 

 muscular effort, enormously to increase 3 30 

 his individual power of locomotion. | 

 The top curve on Fig. 2 shows, in 

 comparison with the other curves of 

 walking and running, his unpaced 

 records on a bicycle, in using which it 

 will be realised that all three causes 

 of I0-.S which occur in running and 

 walking are obviated. You will notice 

 a similar difference in speed as the 

 distance varies to that which is made 

 evident in the curves for walking and 

 running. For the distance of 100 miles 

 the average speed is thus only 21 miles 

 an hour, while that for \ mile is more 

 than 35 miles an hour. In view of 

 the results shown by the curve, it is 

 not surprising that the bicycle has 

 entered largely into the conditions of 

 modern life. I am not able to give you 



any exact figures of the quantity of bicycles turned out 

 each year in this country, but I can tell you that in the 

 Post Office alone there are now 12,000 bicycles emploved, 

 and their number is always on the increase ; the distance 

 covered on them by men and boys in the year is more 

 than 120,000,000 miles 



1 have not dealt with paced bicycle records, as surli .ii.- 

 not the result of muscular effort, but of being pushed along 

 bv the current of wind which follows up the pacing 

 machine such as occurs when a man on a " push " bicvcle 

 is paced by a motor vehicle. In a record first set up in 

 America for 60 miles an hour on a bicycle, a man was paced 

 by a locomotive engine, running at 60 miles an hour along 

 a special track ; the r"der was nearly killed when he tried 

 to drop behind, owing to the whirlwind which was being 

 dragged along by the engine ; ultimatelv his life was saved 

 by his being lifted bodily off his bicycle on to the loco- 

 motive. Theie is no record as to what became of the bicvcle. 



I 



Curioutily enough, liJiiiij; .ii, : 



skating are almost the liame, and far b<-low that on th4 

 bicycle, which 1 think prove* distinctly that the re» iprin at- 

 ing movement of the limbs limits man't> powers. wh< ' 

 he 1% sliding on llw ice or ui>ing wheels as with r< 

 skates. This is so, notwithstanding that he carries ai-»i|^ , 

 with him when on a bicycle the extra weight of th»J 

 bicycle, but the reciprocating movement of his legs !» i»o( 

 slow, owing to the gearing up of the driving whw-l, as to| 

 give him the material advantage shown by the resp«(iiv 

 curves. Further, in skating, there is no doubt that 

 movement of his limbs entails a certain amount of r: 

 and falling; as well as reciprocating motion and conscqui nt 

 loss which occurs in running. 



Now, in theory, the wheel is perfect, and in the case o( 

 a fwrfectly hard, circular wheel, rolling on a perfectly hard 

 track, there should be no resistance. This you can well 



' 30 



NO. 2166. VOL. 86] 



Fig. 3.— Graphical Table of Maximum Speeds. 



I imagine from the lantern model which I now show in 

 operation. In this there is no appreciable resistance, but 

 it is just in this direction that the wheel has defects 

 unknown to nature's methods, since men and animals move 

 upon the ankle joint in a quite superior way to the rolling 

 of an ordinary wheel. In passing I may rfmark that 

 till more man improves the roads, and the higher his 

 I standard of locomotion becomes, the more will he feel the 

 I need of a mechanical walking machine (it will be a 'walking 

 ■ machine, tj^ough possibly moving at 20 miles per hour) to 

 progress over parts of the earth where roads do not exist, 

 or are still in an evil condition. The better his mechanical 

 appliances for producing such a walking machine, the 

 sooner will this come about, as this is really a vital factor 

 in the solution of the problem. No wheel, however, is 

 quite hard and round, and no road is quite hard and 

 smooth, and there is always an arc of contact, more 

 or less appreciable, which causes a loss, since rubbing 



