Thus encouraged, the matron drew near to the brink; and even Mr. Bumble himself, impelled by curiousity, ventured to do the same.
There are no more uses of "impel" in the book.
Show samples from other sources
When in the Course of human events, it becomes necessary for one people to dissolve the political bands which have connected them with another ... that they should declare the causes which impel them to the separation.
Thomas Jefferson -- The Declaration of Independence
The only explanation which I could think of for this mass exodus was that I had somehow disturbed the wolves so seriously they had felt impelled to abandon their den.