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This compass was acquired from it's second owner, who purchased it from a fellow geology instructor in 1972, and used it in his classes at the University of Colorado.
Specifications:
- Manufacturer: William Ainsworth and Sons.
- Date of Manufacture: Early 1960s based on the serial number.
- Materials:
- Body: Green 'crinkle'-painted Aluminum
- Crystal: Glass, retained by a rubber ring.
- Hinges: Black-laquered brass.
- Sights: Black-laquered brass.
- Size: 3-1/16 X 2-3/4 X 1-1/4 closed
- Needle: Steel
- Magnet: AlNiCo
- Damping: Induction
- Pivot: Jewelled
- Graduations: Quadrants by 10 degrees, with tick marks at every degree and longer marks at every 5 degrees.
- Declination: Adjustable via screw-driven gear.
- Weight: 8.5 oz
- Stop: Rubber button actuated by lid when closed.
- Description: This is a genuine Ainsworth Brunton Pocket Transit. The body of the instrument is painted aluminum, in a green 'crinkle' finish. The face is black painted aluminum, with white graduation marks. The inside of the lid contains a round mirror with an oval sighting window at the hinge side, and a center-line which is engraved perpendicular to the hinge, bisecting the oval sighting window. The side opposite the hinge has the small folding sight, which folds flat against the outside of the lid. The long sight is attached to the body of the compass, opposite the hinge. The long sight has a fold-up tip that allows the instrument to be laid out with an 8-1/4 inch sight baseline.
- Condition: Excellent. Needle swings free on jewelled bearing. Sights are present and intact, and move easily. The mirror is unbroken, clear, and free of any oxidization. Retaining rings are in place and in good condition. Level vials are intact, the fluid is present and clear and the bubbles have been retained.
- Damage: Various nicks and scratches on outer case, with small chips of paint missing. The previous owner had hand-engraved his name and the word "Geology" onto the outside of the lid. Declination screw turns the ring freely.
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