Maker

Kern, Aarau, Switzerland

Model

Cat No 458

Serial Number

n/a

Dimensions

103 x 95 x 75 mm

Image

Description

This small zenith/nadir plummet fits on the KERN centring system (on tripods, trivets and pillars) and permits centring under a mark above ('roof marks' in tunnels, mines) or below. The magnification of the small telescope (focusable) is 2.6 x. The sensitivity of the plate level is 50-60"/2 mm.

The plumbline can be established to about 10". maximum sighting distance is 10-15 m.

There is a screw on the side that allows to switch between zenith (up) and nadir (down) directions. The lower part (with footscrews) is the same as for traversing targets (Cat No 459, see item 0242).

The wooden box includes a fitting that allows a centring thread to be inserted into the centring device for a direct attachment to trivets (see item 0241) and, possibly, for use on older tripods.

Marked (engraved) : Kern Aarau Suisse

History & comments

pre 1971

Conservation

In wooden box with drawer lid (127 x 132 x 32 mm)

Condition

some paint damage, in working order

Remarks

Advertised in catalogues/brochures in 1965 and 1971.

Donated by the Sydney Water Board. Engraved '9R'.

Dates

Catalogued in 2012 by JMR. Photo by JMR.