Black and white halftone photograph of the Hydraulic Suction Dredge "Primrose" working on the fourth Welland Canal, c. 1920. From the booklet "Welland Ship Canal (Under Construction)" by the Department of Railways and Canals.
Black and white photogravure from the book "Niagara Falls Photo-Gravures from Recent Negatives of the Albertype Company, New York" by A. Wittemann, captioned “Ice mountain - American fall," c. 1890-1892.