E. B. Temple, Transactions of the American Society of Civil Engineers…
“ The surface of the platforms, with the exception of the edges, is to be of brick, on a concrete base; and, if settlement occurs, the bricks can be taken up and re-surfaced. The tops of the platforms are 3 ft. 10 in. above the top of the rail and on a level with the floors of the cars, so that passengers may enter or leave trains without using steps, as all cars which will enter the Pennsylvania Station, New York City, are to be [77] provided with vestibules having trap-doors in the floor to give access to either high or low platforms. ”
