A muzzle loading cannon, at Fort Niagara, from Curwood's 1909 The Great Lakes.
Unknown author<span style="display: none;">Unknown author</span>
circa prior to 1909
<a rel="nofollow" class="external text" href="https://books.google.ca/books?id=f5O7vQEACAAJ&amp;dq=The+Great+Lakes:+The+Vessels+that+Plough+Them&amp;hl=en&amp;sa=X&amp;ved=0ahUKEwivlP-Fpb7nAhVineAKHVUfC_wQ6AEIKTAA"><i>The Great Lakes: The Vessels that Plough Them, Their Owners, The Sailors, and Their Cargoes</i></a>