Both Uses of

unprecedented

in

The House of the Seven Gables

The child, staring with round eyes at this instance of liberality, wholly unprecedented in his large experience of cent-shops, took the man of gingerbread, and quitted the premises.†
Chpt 3 *

unprecedented = not having happened before; or nothing similar having happened before

But Hepzibah could not rid herself of the sense of something unprecedented at that instant passing and soon to be accomplished.†
Chpt 16