McAlpine, William J., New York arcade railway as projected… (1884)
“ In many places the walls of the tunnels have been founded from ten to twenty feet lower than the foundations of adjacent buildings, and in some places the foundations of these adjacent buildings, many being very old and of decayed material, have been underpinned from six to sixteen feet in depth. But in all these cases, through the admirable plans of the English Engineers, the Underground Railway has been constructed with complete success, and without causing any injury whatever to the buildings. ”
