- The Library Shop
- Privacy Policy
- Rules and Regulations
- Using the Internet
- Website Terms and Conditions
- Gifts of Materials to NYPL
-
© The New York Public Library, 2024
The New York Public Library is a 501(c)(3) | EIN 13-1887440
Photographs of the Catskill water supply system in process of construction
General Research Division, The New York Public Library. "Yonkers pressure tunnel. Steel ribs for concrete forms, made up of 5-inch I-beams spaced 3 feet apart. Lagging plates placed as concrete is built up from the invert. Contract 54. May 1, 1912." The New York Public Library Digital Collections. 1918. https://qa-digitalcollections.nypl.org/items/510d47da-ddbe-a3d9-e040-e00a18064a99
General Research Division, The New York Public Library. "Yonkers pressure tunnel. Steel ribs for concrete forms, made up of 5-inch I-beams spaced 3 feet apart. Lagging plates placed as concrete is built up from the invert. Contract 54. May 1, 1912." New York Public Library Digital Collections. Accessed November 29, 2024. https://qa-digitalcollections.nypl.org/items/510d47da-ddbe-a3d9-e040-e00a18064a99
General Research Division, The New York Public Library. (1918). Yonkers pressure tunnel. Steel ribs for concrete forms, made up of 5-inch I-beams spaced 3 feet apart. Lagging plates placed as concrete is built up from the invert. Contract 54. May 1, 1912. Retrieved from https://qa-digitalcollections.nypl.org/items/510d47da-ddbe-a3d9-e040-e00a18064a99
<ref name=NYPL>{{cite web | url=https://qa-digitalcollections.nypl.org/items/510d47da-ddbe-a3d9-e040-e00a18064a99 | title=
(still image)
Yonkers pressure tunnel. Steel ribs for concrete forms, made up of 5-inch I-beams spaced 3 feet apart. Lagging plates placed as concrete is built up from the invert. Contract 54. May 1, 1912., (1918)|author=Digital Collections, The New York Public Library |accessdate=November 29, 2024 |publisher=The New York Public Library, Astor, Lenox, and Tilden Foundations}}</ref>