The Metropolitan Board of Works shall have Power to make, widen, or improve any Streets, Roads, or Ways, for facilitating the Passage and Traffic between different Parts of the Metropolis, or to contribute and join with any Persons in any such Improvements as aforesaid, and to take, by Agreement or by Gift, any Land, Rights in Land, or Property, for the Purposes aforesaid (or otherwise) for the Improvement of the Metropolis, on such Terms and Conditions as they may think fit; and such Board, where it appears to them that further Powers are required for the Purpose of any Work for the Improvement of the Metropolis or public Benefit of the Inhabitants thereof, may make Applications to Parliament for that Purpose, and the Expenses of such Application may be defrayed as other Expenses of the said Board: Provided always, that before the Metropolitan Board of Works commence any such Works the estimated Expense whereof shall exceed Fifty thousand Pounds the Plan of such Works, together with an Estimate of the Cost of carrying the same into execution, shall be submitted by such Board to the Commissioners of Her Majesty's Works and Public Buildings; and no such Plan shall be carried into effect until the same has been approved by such Commissioners ; and no such Works shall be commenced in Cases where the estimated Expense thereof shall exceed the Sum of One hundred thousand Pounds without the previous Sanction of Parliament.