I think it's a critique of the modern technological society. The people of the town (including, in the beginning, the carpenter) are all linked to The Mill (Le Moulin): when it is stopped, they are powerless; when it spins, they can move; when it goes wild, they are frantic and out of control.
During the storm, one cog (the carpenter's) breaks off; the carpenter finds himself then able to live at a steady, happy pace (now that his link with technology is broken). He invites his wife into this life, but she cannot enjoy it (or him), because she is still linked.
He then attacks The Mill, as he now recognizes the trouble it causes; note that the people cannot fight him unless the Mill is turning.
But, in the end, The Mill collapses and falls into the river, where it will now turn steadily forever. The people of the town are glad, as they can now live the slow, steady life that the carpenter discovered. |