Preliminary identification
Photo reference
3 uploaded photos
Overview
This is a classic Brunton Pocket Transit, a precision combination instrument featuring a compass, clinometer, level, and plumb. Housed in a rugged, powder-coated green cast-aluminum case, it is the quintessential tool of field geologists, surveyors, and forestry professionals worldwide.
Story
Invented in 1894 by Canadian geologist David W. Brunton, this pocket transit revolutionized field mapping. By combining a compass, level, and clinometer into one handheld device, it freed explorers from carrying heavy, separate surveying equipment.
Maker / Origin
David W. Brunton patented his pocket transit while working as a mining engineer in Colorado. He partnered with William Ainsworth to manufacture the device, which quickly became the global gold standard for field science. The company eventually relocated to Riverton, Wyoming, where they continued to hand-assemble these legendary instruments.
Condition & Value
The compass appears to be in excellent vintage condition with minimal paint loss on the green aluminum casing. The mirror is clear, the glass face is unscratched, and the level bubbles are intact. Excellent functional condition like this commands a premium.
Full Research
Sold comps, value drivers, and venue guidance pulled from recent auction results.
Build on this identification
Layer in sold comps, value drivers, and venue guidance.
Comparable demand stays strongest where maker, originality, and venue confidence line up. Broader examples still trade, but the range tightens quickly when provenance, condition, or selling lane fit is missing.
Best Venue
Specialty auction or a focused dealer with buyers already in this lane.
Signed example with light edge wear and original frame.
Comparable format with stronger provenance and cleaner surface.
Smaller related piece with visible craquelure and trimmed margins.
Period match with softer condition and weaker subject matter.
Close market lane comp with similar material and presentation.