An Improved Centre-marking Apparatus for use with Plumbing Instruments

Abstract

Abstract 6166. Tallack, H. T. March 23. Plumbing-instruments; surveying- instruments.-A device for marking on the ground, or on a post or plate let into the ground, a point which is exactly beneath a position plumbed by a plumb bob, nadir telescope, or other instrument comprises a rigid base A, with levelling screws B and levels C, C', and sliding frames D, E, the inner one E carrying the socket H of a spring centre punch I. To mark the position, the frames D, E are adjusted by screws F, G, until the centre of cross-lines on the top of the punch is beneath the plumbbob or in the line of collimation of an opticil plumbing-instrument.

Inventors

• 👤 Henry Thomas Tallack

Bibliographic Details