The Faber-Castell 111/38 Stadia 360° desktop surveyor's rule seems to be extremely rare. My searches of the Internet have brought up a few examples of the 111/38 Stadia 400g, but almost none of the 360° version. My father found this one in an antique shop, in nearly mint condtion, complete with its case. Thanks Dad!
The 111/38 is a full-sized rule, with scales on only one side of the stator, but both sides of the slide. The front contains L, A, B, CI, C, D, P, S, and T scales (the P scale computes 1-x2, which is also the cosine of the angle on S) These scales are all self-documenting, with the scale name at the left end of the scale, and its mathematical formula at the right end. A noticeable ommission is the K scale. Perhaps surveyors don't have much need to compute cubes or cube roots.