Значения термина impalpably fine на английском

Over all-overmen, decks, rope-coils-inthe cabin, in the engine-room-between skylight leaves-onevery shelf, in every cranny-laya purplish ash or dust, very impalpably fine.

Shaving of metal peel off, as other edges turn, so impalpably fine that five thousand must be laid side by side to make an inch.