Columbia subject headings:
Civil engineering--Canada--History--19th century.
Civil engineering--United States--History--19th century.
Mechanical engineering--Canada--History--19th century.
Mechanical engineering--United States--History--19th century.
Photography in engineering--History--19th century.
Public works--Canada--History--19th century.
Public works--United States--History--19th century.
Harvard subject headings:
Canada--Public works--History--19th century.
Civil engineering--Canada--History--19th century.
Civil engineering--United States--History--19th century.
Mechanical engineering--Canada--History--19th century.
Mechanical engineering--United States--History--19th century.
Photography in engineering--History--19th century.
Public works--Canada--History--19th century.
Public works--United States--History--19th century.
Princeton subject headings:
Civil engineering--Canada--History--19th century.
Civil engineering--United States--History--19th century.
Mechanical engineering--Canada--History--19th century.
Mechanical engineering--United States--History--19th century.
Photography in engineering--History--19th century.
Public works--Canada--History--19th century.
Public works--United States--History--19th century.