100 pounder <a href="https://en.wikipedia.org/wiki/Parrott_rifles" class="extiw" title="en:Parrott rifles">Parrott rifles</a> at Union Battery Rosecrans are trained upon Battery Wagner.
Unknown author<span style="display: none;">Unknown author</span>
<ul><li><i><a rel="nofollow" class="external text" href="https://archive.org/stream/photographichist05mill#page/114/mode/1up">The Photographic History of The Civil War in Ten Volumes: Volume Five, Forts and Artillery</a></i>. The Review of Reviews Co., New York. 1911. p. 114.</li></ul>