a form of contract was adopted and an invitation issued by the Board to contractors to bid for the construction and operation of the railroad.  There were two bidders, one of whom was John B. McDonald, whose terms submitted under the invitation were accepted on January 15, 1900; and, for the first time, it seemed as if a beginning might be made in the actual construction of the rapid transit road.  The letter of invitation to contractors required that every proposal should be accompanied by a certified check upon a National or State Bank, payable to the order of the Comptroller, for $150,000, and that within ten days after acceptance, or within such further period as might be prescribed by the Board, the contract should be duly executed and delivered.  The amount to be paid by the city for the construction was $35,000,000 and an additional sum not to exceed $2,750,000 for terminals, station sites, and other purposes.  The construction was to be completed in four years and a half, and the term of the lease from the city to the contractor was fixed at fifty years, with a renewal, at the option of the contractor, for twenty-five years at a rental to be agreed upon by the city, not less than the average rental for the then preceding ten years.  The rental for the fifty-year term was fixed at an amount equal to the annual interest upon the bonds issued by the city for construction and 1 per cent. additional, such 1 per cent. during the first ten years to be contingent in part upon the earnings of the road.  To secure the performance of the contract by Mr. McDonald the city required him to deposit $1,000,000 in cash as security for construction, to furnish a bond with surety for $5,000,000 as security for construction and equipment, and to furnish another bond of $1,000,000 as continuing security for the performance of the contract.  The city in addition to this security had, under the provisions of the Rapid Transit Act, a first lien on the equipment, and it should be mentioned that at the expiration of the lease and renewals (if any) the equipment is to be turned over to the city, pending an agreement or arbitration upon the question of the price to be paid for it by the city.  The contract (which covered about 200 printed pages) was minute in detail as to the work to be done, and sweeping powers of supervision were given the city through the Chief Engineer of the Board, who by the contract was made arbiter of all questions that might arise as to the interpretation of the plans and specifications.  The city had been fortunate in securing for the preparation of plans the services of Mr. William Barclay Parsons, one of the foremost engineers of the country.  For years as Chief Engineer of the Board he had studied and developed the various plans and it was he who was to superintend on behalf of the city the completion of the work.