"To all intents and purposes, it is," said Vinson flatly. "Even to evolution. Consider the life of machinery. It must have started with the little automatic repair machines. There are some twenty-two thousand electron tubes in each one, you know, and so we devised a gadget that went down the aisles and replaced them one after another automatically. Now, the machine must have started from that crude affair and by using its cable-clamps, worked on another machine capable of more complex action. Sort of like a lobster fashioning a hammer out of a rock with its claws. Then the more complex machine must have rebuilt the repair-gadgets, making them even more facile--and so on until we have the completely capable machine. "So," he said with a grim smile, "if that isn't evolution, what is?" "But evolution is a natural process." "Is it necessarily so? Remember, we humans breed bigger and better cattle, dogs, birds, and plants. We are making evolution less a natural process in every form of domesticated and semi-domesticated life--but our own. By its own rules, the human race is sheer mongrel!" "But mechanical evolution--?" "Not ridiculous as you might think," said Vinson. "What is mutation? Only what we might call an 'engineering change in design'." "You make it sound terribly logical," said Admiral Sarne. "But what are we to do?" "Narina and I intend to investigate this cube." Lloyd nodded glumly. "We might stand guard, but how can you stand guard with a gun that might not fire?" "Yes, Vinson; if as you state only machines with the rudimentary electronic nervous system can be under mechanistic control, why then did our gunners find themselves unable to even press the mechanical triggers? This was after they found the fire-control devices inoperable." "Such a simple lever and spur device would, of course, have nothing equivalent to muscle--" "Equivalent to muscle?" exploded Admiral Sarne. "Of course. A servo mechanism is an electronic muscle. Anyway, lacking such ability to resist force, some other means--perhaps some sort of super-powerful magnetic was in operation." "Powerful enough to keep a sliver of steel tight against a block of steel against hammering?" "Perhaps not directly. But those are precision parts, are they not?" "The finest." "Magnetostriction. The deformation of ferrous materials under powerful magnetic fields. The very pins that the trigger rotated upon might have expanded sidewise jamming itself in the slot." Lloyd shook his head. "We'll try keeping guard, but it may be with fixed bayonet against tanks, Vinson. God! I feel helpless as a kitten." President Comstock stood up. "So do we all. But we are--at long last and praise Heaven--both on the same side of the fence. We can go far together. And the first thing is to permit Vinson and Miss Varada to go to work together. You," he said to them, "will work unmolested in the Department of Applied Physics Laboratory at the Bureau of Standards."