FO's in Flanders

Flanders is flat country ("Stupid Flanders" - Homer Simpson). The famous "Hill 60" in the Ypre Salient was nothing but a spoil pile left from digging a railway cutting. It was so named because 6o meters was its height above sea level. The hotly contested "high ground" of the Messines Ridge averaged only 20 to 30 feet higher than the surrounding countryside. Flat.
My job back in my Oregon Army National Guard days was that of an artillery observer (MOS 13F). That's the guys, put simply, who sit on the hill and watch where the big bullets land and tell the other guys on the guns how to correct their aim. We always practiced at Yakima Firing Center in Central Washington. A high, cold, desolate place where the jackrabbits would carry lunch boxes if there were any jackrabbits. Lots of hills though.
So, what do you do when you're short on high places? The Great War saw the first use of telephone-equipped balloons for observation and, to a very limited degree, airplanes.
Mostly though; guys on the ground "observing the fall of shot".
First photo: one of my favorite ARTY pictures, mostly because of the observation platform. It shows a French '75 (pre-war from the uniforms) and the tongue of the limber, when tilted up, is fitted with a nice, little steel plate, shaped just like a French officer, with shelves at foot and elbow for observation. Obviously fraught with problems in the real world, but a very elegant solution.
More often people had to be more resourceful in getting off the ground. Buildings were always good, but for the same reason, were always targets. Trees work - while there are trees. The next photo is of a cozy corner of the Salient during the muddy, bloody debacle, officially known as "The Third Battle of Ypres" and unofficially as "Passchendaele". Note that, of the bare poles remaining, one has steps nailed to it to be climbed by someone far braver than I.

The most interesting, to me, were the armored trees. To the left you'll see a French sketch of one and below that an Australian, snipers post at Messines. The Germans were obviously paying attention so these had to made to mimick a specific tree on the line. Measurements were taken, drawings and, presumably photos so that the engineers could build it behind the lines in sections of armor plate and papier mache. Then it had to brought up to the front, the existing tree taken down and the new one put up - all in the course of one long night. If extra height was needed, the parapet was built up to boost it a bit. This meant that the nightime workload included "fading" the rise back into the parapet by gradually building the parapet up for a distance of fifty feet or so on either side. The point being: If Fritz catches on that something's different about this tree, it will become very interesting to the wrong artillery.
As might be expected, armor notwithstanding, this was not a warm and fuzzy place to be. In Lyn MacDonald's book "They Called it Passchendaele" she describes the feeling of one Major Rory MacLeod, commander of battery C of the 241st Royal Artillery: "It was the first time [he] had ever made use of such an observation post and when he climbed into it he had a nasty feeling that it was also going to be his last."