20.O33 [Bultehoek, at the Western Edge of Houthulst Forest] December 18, 1917
Covers an area equivalent to portions of squares O27, 32, and 33 on the corresponding WWI map sheet 20. Negative roll 9B, photo 179. Brickfield located at the right edge of the photo, just below the half-way point. Annotations on recto: north arrow pointing slightly right of straight up. Annotations on verso: "1st Div. (Left) Front." WWI Aerial Photograph Collection: Box 1, Envelope 36.