Nestler 26 operations Machine Time slide rule Germany 1940

This early slide rule comes in a leather sleeve, both signed with the Werner Schmidt name and an address in Germany, not sure it was the company that sold it or the name of the craftsman that owned it. Because this is a 1940’s Nestler model 26 special slide rule for operations / Betriebsrechenschiebier for craftsman using machines and making calculation of machining times for different activities and materials.  The later redesigned model was called the “Mecanica” with the later 0260 designation. This one is just a bit larger and has a special large cursor with 3 long and 3 red short hairlines under the dedicated symbols in the upper rim. There are addittional scales on the back of the slider and cm and inches scales on the sides as well as table on the back in German. The rule and cursor are complete with some signs of use and age (mostly some darkening of the white laminate. It measures 31 cm or 12 1/2 inches long. The heavy leather sleeve is complete and it has small storage marks only, no Nestler brand, yet very professionally made and a perfect fit. Do check the video below on how to work your vintage man tool : slide rule operation instructions!