License, verbatimCC0
The Smithsonian Institution: Open Access image dedicated to the public domain under Creative Commons Zero (CC0); usage.access=CC0 on the media record itself.
Dunmore and Critcherson, active 1865-1875. Arctic Regions: The Glacier as seen Flowing or Being Forced Down between the Hills, Ploughing up a Moraine of Earth and Rocks, Twenty to Thirty Feet High, 1869, published 1873. Smithsonian Institution.