The board of commissioners may pay out of the county funds, not otherwise appropriated and upon proper vouchers being given, a sum of money, annually, to county firemen's associations, considered necessary to assist in paying the running expenses of conducting a program on fire prevention education. When any such association is comprised of residents of more than one county, the commissioners of said respective counties may, jointly, pay said sum in such proportion as they shall agree.
16 P.S. § 9308