CLOCK MECHANISMS. 49 



that a man shall be called a clock, so people listen to the 

 monotonous "tick," "tick," of the philosophical repeater 

 until they get weary, and then, in order to arouse their 

 mechanical energies and prevent them from going to sleep, 

 it is necessary for the great clock to amuse them by the 

 exhibition of instruments of a very remarkable kind, which, 

 besides doing the usual round of clock-work, cry out at 

 certain intervals " cuckoo," and perform yet more wonderful 

 tricks. Such perfection of mechanical skill ought of course 

 to bring conviction to every mechanical mind. Unhappily, 

 however, there still remain a few sceptical people who, in 

 spite of the most clear and convincing clock-demonstration 

 are foolish enough to persuade themselves, and to try to 

 persuade others, that they are not quite convinced that they 

 are veritable clocks, or that any living organisms are clocks 

 in truth ; but even such as these are ready to admit that 

 there is very much in the clock view of things, and that the 

 clock doctrine is at least at this time very useful as "a work- 

 ing hypothesis." It is very confidently predicted that in the 

 course of a short time we shall obtain conclusive evidence 

 that some organisms, like some instruments, will go when 

 they are wound up, and strike an alarum, and astonish, or 

 simply note the passing events, and count the hours and 

 minutes, according to the properties of the particular mate- 

 rials constituting the mechanism originally introduced by 

 the clockmaker. And when the clocks shall be worn out 

 they will be cast into the melting pot, from the contents of 

 which the next generation of clocks will spring, according 

 to the inexorable laws of clock evolution which are now 

 nearly established ! 



There is a grand simplicity in the doctrine that a living 







