An act to explain, amend, and render more effectual two acts, made in the thirty-first year of the reign of King George the second, and in the twenty-ninth year of the reign of His Present Majesty, for draining and preserving certain Fen lands and low grounds in the Isle of Ely and county of Cambridge, between the Cam otherwise Grant, Ouse, and Mildenhall Rivers, and bounded on the south east by the hard lands of Isleham, Fordham, Soham, and Wicken, and for empowering the governor, bailiffs, and commonalty of the company of conservators of the great level of the fens, called Bedford Level, to sell certain lands within the said limits, commonly called invested lands; and for laying certain rates on vessels navigated upon the said rivers, towards supporting the banks thereof.