overall in case: 11 5/8 in x 6 3/4 in x 4 3/4 in; 29.5275 cm x 17.145 cm x 12.065 cm
Object Name:
theodolite
Place made:
Switzerland
Description:
Heinrich Wild designed this DKM2 (a double-circle theodolite with an optical micrometer) for Kern in the 1930s. Like the T2 manufactured by Wild in Heerbrugg, the DKM2 is a lightweight instrument with a steel frame. The horizontal and vertical circles are glass, and read directly to single seconds. The telescope is equipped with stadia wires, and so can be used for tachymetry. An auxiliary eyepiece lying alongside the telescope allows the user to read either circle without moving away from the station. Here, however, the 2 scales are read through the optical micrometer with reference to a centrally located index, giving the arithmetic mean of 2 diametrically opposed points on the circle. In 1955, an instrument of this sort, with tripod, cost $1,221. This example is marked "Kern AARAU SUISSE SWITZERLAND No 81066 DKM2." It was probably made in the 1960s, and it came to the Smithsonian in 1979.
Ref: Kern & Co., Ltd, <i>Double Circle Theodolites</i> (about 1959).
