The county commissioners of any county may purchase such machinery for the preparation of road material and the construction and maintenance of roads as they deem necessary and pay for the same out of the general funds of the county. Such machinery may be rented by the county commissioners to any of the townships within such county applying for same, under such regulations and at such rentals as the county commissioners shall prescribe and fix. All machinery purchased under the provisions of this section shall be operated only by persons employed for that purpose by and under the direct supervision of the county commissioners.
16 P.S. § 5934