"And whereas it is expedient that the London, Tilbury and Southend Railway Company, The Lessees, and the Great Eastern and London and Blackwall Railway Companies respectively should be enabled to agree upon such alterations in the terms of the lease, in the arrangements for working the said railway, and in the apportionment of the receipts and expenses as by this Act authorized; and that the Great Eastern and London and Blackwall Railway Companies, jointly or severally, should be empowered to take a lease or transfer of the existing lease of the London, Tilbury and Southend Railway, upon such terms and conditions as by this Act authorized."
"The two companies"--that is the Eastern Counties and the London and Blackwall Companies --"may enter into agreements in respect to the working, maintenance, and management of the Extension Railway , or any part thereof."