BY B. H. M. HEWETT AND W. L. BROWN, MEMBERS, AM. SOC. C. E.

[A] Presented at the meeting of June 1st, 1910.

Transactions of the American Society of Civil Engineers, Vol. LXVIII, Sept. 1910 The New York Tunnel Extension of the Pennsylvania Railroad. The North River Tunnels. Paper No. 1155 · 第 7 / 55 题