MAKER: Zulauf & Zschokke

c. 1900

SIGNED:Zulauf & Zschokke, Zurich

SERIAL NUMBER: 1752

AUTHOR: Barry Sobel, with information about the history of the company by Brian Stevenson

EDITOR: Joseph Zeligs

The nosepiece provides things convenient for petrographic work. These include two centering screws for the nosepiece. With the attached quick-change mechanism, and an objective attached, the centering of any of the objectives provides good centering of all of them. The objectives each have a ring-shaped adapter (see inset) in place which fits into the quick change device. Via the clutch, this ring is held up against a matching round cavity of the upper part of the quick change device, assuring each objective slips into the same centered position. The nosepiece also includes a slide-in analyzing prism, and a slot for waveplates.

Changing an objective is simple. The clutch handle is squeezed, allowing quick exchange or insertion of an objective, and releasing one's grip automatically keeps the objective securely in place in the matching round recess in the top half of the clutch: