Section 101(1) in The Calcutta Improvement Act, 1911
(1)All money paid into any sinking fund shall as soon as possible be invested, under the orders of the Board, in -(a)Government securities, or(b)securities guaranteed [by the Central or any State Government] [Words substituted by the Government of India (Adaptation of India Laws) Order, 1937 and the Adaptation of Laws Order, 1950, respectively.], or(c)Calcutta Municipal debentures, or(d)debentures issued by the Commissioners for the Port of Calcutta, or(e)debentures issued by the Board,in the joint names of the Secretary to the Government of [West Bengal] [Words substituted by the Indian Independence (Adaptation of Bengal and Punjab Acts) Order, 1948.]in the Financial Department and the Accountant General of [West Bengal] [Words substituted by the Indian Independence (Adaptation of Bengal and Punjab Acts) Order, 1948.], to be held by them as trustees for the purpose of repaying from time to time the debentures issued by Board.
