I did a little investigating, and found that the above image, which is inscribed on the verso with the ever so helpful “Cologne — General view with Bridges of Boats — 3328,” is actually a photograph of the Deutz Ship Bridge. The Deutz Ship Bridge spanned the Rhine at Cologne. The Library of congress images are dated c. 1890-1900, but I’m going to assume that “my” photo is contemporary with the Katz Castle photo, which would make it at the earlier end of the range.
Pontoon bridge from Deutz, Cologne, the Rhine, Germany
Title: [Pontoon bridge from Deutz, Cologne, the Rhine, Germany]
Date Created/Published: [between ca. 1890 and ca. 1900].
Reproduction Number: LC-DIG-ppmsca-00804 (digital file from original)
Rights Advisory: No known restrictions on publication.
Call Number: LOT 13411, no. 0804 [item] [P&P]
Repository: Library of Congress Prints and Photographs Division Washington, D.C. 20540 USA
http://www.loc.gov/pictures/item/2002714080/
Pontoon bridge from Deutz, Cologne, the Rhine, Germany
Title: [Pontoon bridge from Deutz, Cologne, the Rhine, Germany]
Date Created/Published: [between ca. 1890 and ca. 1900].
Reproduction Number: LC-DIG-ppmsca-00805 (digital file from original)
Rights Advisory: No known restrictions on publication.
Call Number: LOT 13411, no. 0805 [item] [P&P]
Repository: Library of Congress Prints and Photographs Division Washington, D.C. 20540 USA
http://www.loc.gov/pictures/item/2002714081/
red paper boat 