Hj Flak Helper Whistle Buy Now Accompanied by seven pages of

Accompanied by seven pages of research papers from the National Archives

Royal Engrs)

Jerram was posted to Dreel Castle

and to further the cause of science

located on Queen Charlotte Island off the coast of British Columbia

Hj Flak Helper Whistle Buy Now Accompanied by seven pages ofHJ Flak Helper Whistle Black with wooden ball housed chamber, unmarked, 18 mm x 64 mm, on 390 mm nylon cord with loop at the end for suspension, light contact, very fine. Footnote: When the ball is present inside the chamber, it alternately blocks and unblocks part of the exit slot. This action produces a warbling alternation of tone that makes the whistle's sound more attention grabbing.