CECIL E. HANSON COLLECTION
ANTIQUE SURVEYING INSTRUMENTS

FOREIGN TRANSITS AND THEODOLITES

Froment - Paris, France, ca 1885*

Serial Number:
Type: Geodetic Dip Needle
Telescope Length:
Diameter of Horizontal Circle:
Needle Length:
Diameter of Vertical Arc:
Height:
Weight:
Box: No
Condition: Good
Found: October, 1966 - Boston, MA
CEH Inventory# FT23

*CEH estimate

CEH - Used to locate and measure  the intensity of magnetic fields, and in mines (possibly for locating ore deposits with magnetic properties, such as magnetite)

This Dip Needle is shown here:

http://physics.kenyon.edu/EarlyApparatus/Electricity/Dip_Needle/Dip_Needle.html