Captain William D. MacDougall, United States Naval Attaché in London, to Office of Naval Intelligence
SENT: 27 April, 1917. TO: Navintel. NO: 13027.
The accurate location of submarine sounds by the California sea lion has been established by Admiralty experiments[.] the procuring of additional animals recommended as urgently required here[.] report by mail subject highly confidential.
Source Note: Cy, DNA, RG 45, Entry 517.