(_e_) The Commissioners were given the broad power to enter into a contract (in the case of more than one road, successive contracts) on behalf of the city for the construction of the road with the person, firm, or corporation which in the opinion of the Board should be best qualified to carry out the contract, and to determine the amount of the bond to be given by the contractor to secure its performance. The essential features of the contract were, however, prescribed by the Act. The contractor in and by the contract for building the road was to agree to fully equip it at his own expense, and the equipment was to include all power houses. He was also to operate the road, as lessee of the city, for a term not to exceed fifty years, upon terms to be included in the contract for construction, which might include provision for renewals of the lease upon such terms as the Board should from time to time determine. The rental was to be at least equal to the amount of interest on the bonds which the city might issue for construction and one per cent. additional. The one per cent. additional might, in the discretion of the Board, be made contingent in part for the first ten years of the lease upon the earnings of the road. The rental was to be applied by the city to the interest on the bonds and the balance was to be paid into the city's general sinking fund for payment of the city's debt or into a sinking fund for the redemption at maturity of the bonds issued for the construction of the rapid transit road, or roads. In addition to the security which might be required by the Board of the contractor for construction and operation, the Act provided that the city should have a first lien upon the equipment of the road to be furnished by the contractor, and at the termination of the lease the city had the privilege of purchasing such equipment from the contractor. (_f_) The city was to furnish the right of way to the contractor free from all claims of abutting property owners. The road was to be the absolute property of the city and to be deemed a part of the public streets and highways. The equipment of the road was to be exempt from taxation. (_g_) The Board was authorized to include in the contract for construction provisions in detail for the supervision of the city, through the Board, over the operation of the road under the lease. One of the most attractive--and, in fact, indispensable features of the scheme--was that the work of construction, instead of being subject to the conflicting control of various departments of the City Government, with their frequent changes in personnel, was under the exclusive supervision and control of the Rapid Transit Board, a conservative and continuous body composed of the two principal officers of the City Government, and five merchants of the very highest standing in the community.