|The transit theodolite is a combination compass and telescope which was a predecessor to today's transit instruments used for land surveying.
The instrument displayed here was made for the survey of the Great Lakes in 1867. It is the only known surviving theodolite made by Berlin instrument maker August Oertling (1803 - 1866). Oregon Agricultural College researcher Dr. W. W. Weniger acquired it as surplus from the U.S. Coast and Geoditic Survey circa 1925. The clear acrylic parts are replica replacements for pieces lost years ago.