construction within city limits. Instead, it allowed the building of a short experimental line at the East Cambridge site. The text included the following proviso: No location for tracks shall be petitioned for in the city of Boston, until at least one mile of the road has been built and operated, nor until the safety and strength of the structure and the rolling stock and motive power shall have been examined and approved by the board of railroad commissioners or by a competent engineer to be appointed by them. Meigs amended his design, and acquired a new patent in 1885. Demonstration The company raised $20,000 cash (about $500,000 in 2020 values), which was enough to build a full-sized experimental model comprising a short section of the elevated railway. This was to demonstrate the benefits and capabilities of the system under widely varying parameters, as demanded by the charter. The 227-foot (69 metre) iron demonstration line was erected on land abutting company headquarters in Bridge Street, and was opened to paying riders in June 1886. The company was permitted to run its line over Bridge Street, to end on property occupied by the hog slaughterhouse of John P. Squire and Company. The actual erection was performed by a separate company founded by Meigs, the Meigs Elevated Railway Construction Company, which was intended to be in charge of construction of future lines. The short length of demonstration line in iron was connected to the car shed by a longer wooden version, intended to test the capabilities of the system. This incorporated construction of several types is discernible in a surviving photo of the setup. The rolling stock comprised three units: a locomotive, a tender and a passenger car. In July 1886, the Scientific American magazine published an article entitled The Meigs Elevated Railway and containing this assertion: Everything has worked in the most satisfactory manner, the train rounding the exceedingly sharp curves easily, and mounting the steep grades without trouble. Promotion A fire, supposedly the result of arson, broke out on the night of February 4, 1887, and destroyed Meigs's car shed as well as burning out the experimental coach. The locomotive and tender escaped. A photo survives of the damage, which Meigs claimed amounted to $10,000 ($250,000 in 2020 values). Meigs wrote an extensive explanation of how his urban transit system would function, complete with diagrams and statistics, and entitled it