It shall be lawful for the county commissioners of any county, having first obtained the approbation of the court of quarter sessions of such county, to sell at public sale any part of any public land reserved for the use of the public buildings not necessary or needed for the use of such public buildings, and to pay the proceeds of such sale into the county treasury of said county, notice of the time and place of such sale to be prescribed by the said court.
16 P.S. § 8371