3. Q.-F. disappearing guns.
4. 12 cm. guns.
5. Machine guns.
6. Searchlight.
CONCEALING A FORT IN A MOTH'S HEAD.
Another example of this method of making secret plans is shown here.
This sketch was made, giving all the particulars that I wanted. I then decided to bury it in such a way that it could not be recognised as a fortress plan if I were caught by the military authorities. One idea which occurred to me was to make it into the doorway of a cathedral or church, but I finally decided on the sketch of the moth's head. Underneath in my note-book I wrote the following words:—
"Head of Dula moth as seen through a magnifying glass. Caught 19.5.12. Magnified about six times size of life." (Meaning scale of 6 inches to the mile.)