Which preposition to use with cappings

of Occurrences 6%

But let's leave this capping of rhymes, Studioso, and follow our late device, that we may maintain our heads in caps, our bellies in provender, and our backs in saddle and bridle.

to Occurrences 2%

And, as a capping to the day, Mrs. Alice Challice stepped out of it.

Which preposition to use with  cappings