Hydrographers of the Navy, 1909-1965. Plate 6 from: <cite class="book" style="font-style:normal">Edgell, J.A. (1965)      <i> Sea Surveys. Britain's Contribution to Hydrography.</i> (2<sup>nd</sup> ed.), Her Majesty's Stationery Office (HMSO)  <small><a href="https://en.wikipedia.org/wiki/Online_Computer_Library_Center" class="extiw" title="en:Online Computer Library Center">OCLC</a>:   <a rel="nofollow" class="external text" href="https://www.worldcat.org/oclc/559403750">559403750</a>. </small></cite>
Edgell, John Augustine, 1880-1962
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