All necessary preliminary expenses actually incurred by the board of any municipality in the making of surveys, estimates of costs and of revenue, employment of engineers or other employees, the giving of notices, taking of options and all other expenses of whatsoever nature, necessary to be paid prior to the issue and delivery of the revenue bonds pursuant to the provisions of this article, may be met and paid in the following manner. Said board may from time to time certify such items of expense to the clerk or recorder of said municipality, directing him to pay the several amounts thereof, and thereupon said clerk or recorder shall at once draw a warrant or warrants upon the treasurer of said municipality, which warrant or warrants shall be paid out of the General Funds of said municipality not otherwise appropriated, without a special appropriation being made therefor by the governing body; or, in case there are no general funds of such municipality not otherwise appropriated, the clerk or recorder shall recommend to the governing body the temporary transfer from other funds of such municipality of a sufficient amount to meet such items of expense, or the making of a temporary loan for such purpose, and such governing body shall thereupon at once make such transfer of funds, or authorize such temporary loan in the same manner that other temporary loans are made by such municipality: Provided, however, That the fund or funds of such municipality from which such payments are made shall be fully reimbursed and repaid by said board out of the first proceeds of the sale of revenue bonds hereinafter provided for, and before any other disbursements are made therefrom, and the amount so advanced to pay such preliminary expenses, shall be a first charge against the proceeds resulting from the sale of such revenue bonds until the same has been repaid as herein provided.