WW2 BRASS CLINOMETER TYPE INSTRUMENT MARKED WITH MILITARY ARROW AND "PALMER" DOES ANYBODY KNOW WHAT THIS IS, HOW IT WAS USED, OR WHAT IT WAS USED FOR? DESCRIPTION: Small brass instrument with half mirror, hanging ring and plumb bob that swings 180° around a strangely calibrated, semi-circular scale. Hanging ring external diameter 25mm. Black square frame attached point to point to create a "diamond", which is half-mirrored. This black frame can be rotated into four positions around the perpendicular axis of the instrument, each position 90° apart and held in place by a spring detent (see black spring assembly on shaft between the scale and the black frame). Brass semi-circular scale with irregular markings, where the distance between 5 and 10 is four times that between 10 and 15, and which distances get shorter as the values increase, except after 30 and 40 where the distances get progressively longer again. A pendulum swings around the fulcrum at the natural centre of the scale. This pivot has a knurled clamp nut that can be tightened to lock the pendulum in any position. The brass block on the pendulum can be slid along the pendulum shaft and has approximately 10mm of possible movement. The wording "1 in" are embossed on the pendulum shaft, which makes one think it could mean one in five, ten etc., according to where the "blade" of the pendulum intersects the scale. If this were so it cannot possibly read right, as one in 55 would be a very shallow angle, around 2%, and one in 5 would be an angle of about 20%, which isn't exactly steep..... but if you apply this, those two values would equate to about 30 degrees of arc, possibly slightly more.... but the arc on the scale extends over 180° for those values, and the values are not constant in their spacing. Overall length of the instrument from top of hanging ring to base of pendulum is 21cm, but it folds to fit into a smaller leather case. Half mirrors do not work on their own. They have to be combined with at least one other mirror in order to bring two targets together into one image, such as in a sextant, mirror clinometer, range finder, etc.... so my thought is this instrument cannot be used on its own, but must be used as an integral part of a larger instrument or weapon. All I really know is that this instrument is rare... there are very few in existence, and there were very few in the early 1950s when they were still in use. The instrument has no "sights" or optics, as would be expected of a clinometer. DOES ANYBODY RECOGNISE THIS INSTRUMENT? I can email, skype or msn more photos if necessary.