All books, records, papers, vouchers, and documents which shall be in the possession of any officer, committee, or board of officers of the town, and which are not needed elsewhere by them in the discharge of official duty, shall be deposited in the office of the town clerk, and shall be there kept and preserved by him as public records of the town. Provided that, if the office of the clerk is not equipped for the safe keeping of the said public records, the clerk may, with the approval of the selectmen, deposit such records in some other safe and suitable place.