The piece of land the boundaries and description whereof are specified in Schedule 2 to this Act shall, from and after the passing of this Act, cease to be vested in the Corporation, and shall be and remain vested in and be the property of the Board, to be used for graving dock and slip, and for other purposes of a like nature, or ancillary thereto. The actual cost of the reclamation of the said piece of land described in Schedule 2 to this Act shall be paid by the Board:
Provided always that if at the expiration of fifteen years from the passing of this Act the said land or any part thereof shall not have been used for any of the purposes aforesaid, then the said land or such part thereof as shall not have been so used shall, upon repayment by the Corporation to the Board (which repayment the Corporation is hereby authorized to make) of the actual cost of the reclamation of so much of such land not used as aforesaid as shall have been reclaimed, revest without conveyance in the Corporation:
Provided that the cost of reclamation herein mentioned shall include the cost of construction of so much of the sea-wall as shall form part of any land reverting as aforesaid. The Board shall in the meantime have power, either by private contract or public auction, to lease any parts of the said land for the time being reclaimed, in such manner, for such terms (not extending beyond the expiration of the said period of fifteen years), at such rents, and for such purposes as the Board shall think fit, and shall pay to the Corporation the rents as and when received, subject to the deduction therefrom of interest at the rate of five per centum per annum upon the cost of the reclamation of so much of such land as shall for the time being be reclaimed; and if such interest shall at any time exceed the amount of the rents received, such excess shall be made good out of first rents to be thereafter received.