author
1882–1954
Best known for a practical First World War-era manual on machine gunnery, this little-documented writer is remembered today through a single surviving work in the public domain. Project Gutenberg lists the author as Harry Douglas, though biographical details remain scarce.
Project Gutenberg credits this author as H. Douglas and gives the alias Harry Douglas, with life dates 1882–1954. The work most clearly associated with him there is Machine gun manual: a complete manual to machine gunnery, originally published in 1917.
The book is a detailed instructional guide covering weapons including the Maxim, Vickers, Lewis, Colt, and Hotchkiss, along with drill, fire orders, and practical notes. That makes Douglas less a literary figure in the usual sense and more a specialist writer whose surviving reputation rests on clear, technical wartime instruction.
Reliable online biographical information beyond those catalog details is very limited, so it is safest to describe him as an early 20th-century military manual author, probably writing from direct professional knowledge, rather than make stronger claims that cannot be confirmed.