All books and material, and all clerical labor or assistance, necessary to make and install such indices of deeds heretofore indexed only in the prothonotary's office of any county in this Commonwealth, whether indexed in the regular grantee and grantor indices or in a separate book or books kept for that purpose, shall be furnished and provided by the county commissioners at the expense of the county, and shall be paid for out of the county treasury.
16 P.S. § 9856