Which preposition to use with inspectorships

of Occurrences 3%

He wished too to unite in all cases the inspectorships of police with the office of stipendiary magistrate, to avoid collision; but the duties of inspector are of a mere ministerial and inferior character, and would not agree well with those of a magistrate.

with Occurrences 1%

The wife had fortunately secured a post as one of the delegates of the Poor Relief Board, an inspectorship with various duties, such as watching over the mothers and children assisted by the board, and reporting thereon.

Which preposition to use with  inspectorships