THE MASTER CONTRIVANCE 233 



vision and swing into parallel lines for distant objects ; 

 the lenses must have a self-adjusting focussing mechanism. 

 On the back of the optic cameras sensitised films would 

 have to be fitted, capable of being continually renewed and 

 of registering the continuous series of pictures presented as 

 the cycle spins its way along streets and roads. Cables of 

 wires (to serve as optic nerves) would be required to carry 

 away the chemical records formed by the landscape pictures 

 as they fell on the sensitised film of the camera to a record 

 office or brain. The machinery fitted as a brain must be 

 able to interpret the chemical records which the optic wires 

 carry to it from the camera and pack them away in such 

 an orderly manner that they can be recalled at the demand 

 of the automaton's will. This is merely the receiving 

 machinery required in the brain. Suppose an approaching 

 vehicle comes within the pictures focussed by the optic 

 cameras, then. its size, shape, speed, and position have to 

 be estimated by the recording mechanism in the fraction 

 of a second. For this end the brain of the automaton 

 must be fitted with machinery for comparing and estimat- 

 ing the impressions which are reaching the registering 

 machinery. This estimating machinery must be one 

 already stored with past pictures of moving vehicles of 

 all kinds — pictures which must be summonsed in an 

 instant and compared with the picture of the approaching 

 danger now signalled from the registering part of the 

 brain. The registering and estimating mechanisms belong 

 to the intelligence department of the brain ; they are 

 powerless unless they can command an executive service. 

 Hence a third or executive mechanism has to be added to 

 the automaton brain — one which can judge the exact 

 degree to which the handle bars must be turned to avoid 

 the approaching vehicle. The handle bars, we shall 

 suppose, are worked by means of reciprocating engines in 

 place of hands and arms. The executive mechanism of 

 the automaton must be connected with the engines which 

 control the handle bar by wires or nerves, and over these 

 wires must be able to dispatch messages — electrical, let us 

 suppose — which will start the guiding engines at the right 



