CHAPTER XXII 



THE MASTER CONTRIVANCE OF THE HUMAN MACHINE 



The most wonderful part of a motor cycle is the con- 

 trivance by which it is controlled and driven. That con- 

 trivance is placed within jthe head of the man who occupies 

 the driver's seat, and is known as the human brain. A 

 motor cycle, however ingeniously it may be designed and 

 engined, becomes a complete and useful machine only 

 when a human brain is fitted to it. Even a human body, 

 robust, supple, and sound in every way, is occasionally 

 provided with a brain of so poor workmanship that it 

 may be incapable of managing even a motor cycle. The 

 human brain, then, must be regarded as an intrinsic part 

 of all machines driven by men — be they running, flying, 

 or swimming machines. All are controlled by the most 

 marvellous of Nature's contrivances — the brain. It is 

 this machine or contrivance which forms the subject of 

 the present chapter. ( 



The brain itself is a machine — by far the most intricate 

 one of which we have any knowledge. We shall throw 

 some light on the nature of the work it can do, if we 

 consider for a moment what we should require of an engineer 

 were he to undertake to supply us with an automaton 

 driver. In the first place the automaton must be able to 

 balance the motor cycle on the straight road as well as in 

 taking sharp corners. That difficulty could probably be 

 got over by applying the principle of the gyrostat ; we shall 

 find that Nature has discovered a simpler way. Then it 

 would have to be fitted with a pair of minute photographic 

 cameras or eyes, set so that they could converge for near 



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