Section 48. The sinking fund commissioners shall have charge of all sinking funds intrusted to them by the city, town or district, and shall invest and reinvest, in the name of the board, all amounts contributed thereto and the income thereof as it accrues, in the particular bonds, notes or certificates of indebtedness for the redemption of which such sinking fund was established, or in other bonds of their city, town or district secured by sinking funds, or in temporary loan notes or certificates of their city, town or district issued in anticipation of taxes, or in securities, except personal securities, in which funds of savings banks may by law be invested; but no part thereof shall be loaned to the city or town except as herein provided. The commissioners may sell such securities and reinvest the proceeds. They shall keep a record of their proceedings, and shall annually make a written report to the city, town or district of the amount and condition of said funds and of the income thereof for the preceding financial year. Their records and the securities belonging to said funds shall at all times be subject to the inspection of the mayor, aldermen, selectmen, or any committee or commissioners of the city, town or district authorized for the purpose. No member of the board shall receive compensation for his services; but the necessary expenses of the board shall be paid by the city, town or district, and the treasurer and secretary thereof shall receive such compensation as shall be fixed by the city, town or district.
When securities for the redemption of which a sinking fund has been established become a part of said sinking fund, the commissioners shall cause a notice to be stamped or written on the face thereof that they are a part of such sinking fund, and are not negotiable; and all coupons thereof, as they are paid, shall be cancelled.