After the expiration of twelve months after the maturity of the pledge, the pawnbroker may proceed to sell the pawned property in the manner herein provided. At least ten days' notice must be given the pledger by mail before the date of sale and also a notice of the proposed sale shall be published in a newspaper printed in and of general circulation within the City at least once, which publication shall be made at least ten days before the date of sale. The sale shall be by public auction and by an auctioneer approved by the Chief of Police. From the proceeds of the sale there shall be deducted the amount of the loan, the accrued interest and the expense of the sale, and the balance shall be paid to the pledger.