Jefferson was bearing down on the small boat with all the inevitability and imponderability of an avalanche.

The imponderability of the men from Lackawanna made them a magnet for the government's deepest suspicions and anxieties.

But if there is going to be fighting and war . . ." his voice trailed off in the midafternoon traffic, lost in imponderability.

They seemed to positively enjoy becoming less and less certain about everything and would come in to dinner saying things like 'Wow, we've just overturned Marrowleaf's Theory of Thaumic Imponderability!