If the board of supervisors shall confirm the action of the county board of education, then the board of supervisors may issue bonds in an amount not to exceed Five Hundred Thousand Dollars ($500,000.00) to bear the expense, or a portion of it, for the construction of such center. The bonds shall be for a period not to exceed twenty-five (25) years at a rate of interest not to exceed six percent (6%) per annum. Said bonds so issued shall be full faith and credit obligations of such county. The principal of and interest on same shall be paid out of funds made available by said board of supervisors by the annual ad valorem tax levied upon all of the taxable property within the county in an amount necessary to pay the interest thereon as the same becomes due to be paid, and the principal of said bonds as the same falls due to be paid.