When loans have been approved by the Board from time to time in such amounts that no sufficient balance is left in the Literary Fund from which to make additional loans, the Board is authorized to sell the bonds, notes or other evidences of debt of the school boards for which such loans are approved for investment of the trust funds of the Virginia Retirement System in such amount as may be approved by the Board of Trustees of the Virginia Retirement System in accordance with the provisions of § 51.1-124.30, in order to make such additional loans.