Signature of <a href="https://en.wikipedia.org/wiki/Geoffrey_Pyke" class="extiw" title="w:Geoffrey Pyke">Geoffrey Pyke</a>. From  National Archive: ADM 1/15677 - Proposals and inventions of Mr Geoffrey Pyke; gravity propelled ball bomb, pykrete and power driven rivers
<a href="//commons.wikimedia.org/wiki/User:Gaius_Cornelius" title="User:Gaius Cornelius">Gaius Cornelius</a>
<span class="int-own-work" lang="en">Own work</span>