Which preposition to use with baseboard

in Occurrences 1%

The source of their delight was not the great ragged hole just over the intruding heads, in the ceiling's lath and plaster, nor was it a whole corner torn off the grand-piano by the somersaulting shell as it leaped from the rent above to the cleaner one it had left at the baseboard in the room's farther end.

Which preposition to use with  baseboard