Wilson magnetometer

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Item Wilson Magnetometer
Item code Acquisition, Magnetics
Description Wilson Magnetometer with Brunton Compass
Manufacturer Ainsworth
Circa 1929
Model 0
Donor Texaco
Location Geoscience Center, Geophysical Society of Houston
Serial number unknown"unknown" is not a number.
Taxonomy horizontal magnetometer

Wilson magnetometer.JPG The Wilson magnetometer consists primarily of an auxiliary arm that attaches to a Brunton pocket transit (compass) with a magnet holder that moves along the arm by means of an adjustable rack and pinion. The quantity measured is the absolute horizontal intensity of the earth's magnetic field with sufficient accuracy for gross regional surveys. The advantages are low cost, portability, ease of computation, and simplicity of operation. The instrument may be used on a plane table or mounted on a tripod. In operation, the device is set up with the compass clamped in its holder, leveled and rotated until the compass needle is aligned to the North index of the compass holder. The auxiliary magnet is placed in its holder with the south-seeking pole toward the compass: the magnet is moved along the arm by the rack and pinion until the compass needle is exact at the 30 degree mark on its holder. The distance of separation noted on the scale of the auxiliary arm may be read and used for rapid calculation of the horizontal magnetic intensity.