Alfred Ely Beach, who bought Scientific American, proposed a Pneumatic postal system and an underground railway to relieve traffic congestion since Broadway was extremely busy. Beach came up with the idea of using a 300 ft. long pneumatic tube instead of electricity to propel cars and made a proposal for the Broadway Pneumatic Underground Railway. This was vehemently opposed by A.T. Stewart and John Jacob Astor. However, In 1868 a new method for building subway tunnels used a retaining wall to allow construction without damaging roadways and buildings was developed called The Shield Method. Beach paid the $350,000 cost for the first prototype. Rides on the one stop train went for 25 cents. 11,000 rides were taken daily translating into over 400,000 total rides in its single year of operation. It closed because of a stock market crash. There is still a plaque at the City Hall Station which is the approximate location of the rail.