Molter Mid – Late circular slide rule pocket watch 1925 Germany

This small round slide rule is pretty rare and has features of the “mid” and “late” model so was probably produced in between deze known models. It  was made around 1925 in the pocket watch style. It has a slotted centre knob with 14mm on both sides (different from ones found before) but “fine” outer milling along the rim as well. The grips on the cursor are opaque rather then clean (see through). It measures ca 6,5 cm or 2.6 inches in diameter. Check the video on how to work your vintage man tool : slide rule operation instructions!