French, 2nd quarter 20th century, unsigned. The 2 1/8" diameter body is made of nickel plated brass, with domed beveled glass faces. The front face is fixed, with a moveable cursor needle; the rear face is moveable as is the cursor needle. The slide rule is in very good working condition.
Swiss, early 1st quarter 20th century, signed in the center of the face "THE MECHANICAL ENGINEER." The 2 1/16" diameter body is made of nickel plated brass, with a flat beveled glass face. The face is moveable with the large knob at the top and the cursor is moveable with the small knob on the side. The slide rule is in good working condition.
