machines. From the primitive flint knife to the modern lathe, 
     from the rude shanty to the perfected dwellings of the 
     present day, from the simple abacus to the enormous 
     calculating machine—what variety from which to extract 
     common characteristics and attempt a useful classification! 
     The notion of a machine is as hard to define as that of a 
     living organism; a great engineer once spoke indeed of an 
     ‘artificial zoology’. But it is not definition or classification 
     that is needed most urgently. 
          Here is how Lafitte put it: ‘Because we are their makers, 
     we have too often deluded ourselves into believing that 
     we knew all there was to know about machines. Although the 
     study and construction of machines of all sorts owes much 
     to advances in mechanics, physics and chemistry, 
     nevertheless mechanology—the science of machines as such, 
     the science of the organized constructions of man—is not a