faber castell 2/83N

this castell is not in perfect condition. usual wear and some fading of colors. it is still highly usable, however, and a most interesting rule to operate.

it is festooned with scales on the front here and on the back.

the right end shows the extensive scales on the front. two sets of tan(x), differential pi scales, reciprocal and reciprocal pi and pythagorean, as well as usual c & d, square, cube, sin(x) and ST.
this is the back! its almost as packed as the front. extensive log scales here and repeated c & d from the front.

rather cool is the w1 & w2 scale which are a folded 20" root scale onto 10" (hence two scales). use these the same as c & d, but more accurate.