For sale is a highly collectible, beautiful antique watchmaker depthing tool (compas aux engrenages). This specialized instrument represents the absolute pinnacle of turn-of-the-century precision layout tools, used to test and establish perfect center-to-center distances for gear trains in pocket watches and marine chronometers.
Features & Details:
• Premium Heavy Brass Workmanship: Exceptionally machined solid brass framework with decorative chiseled beveling and knurled adjustment hardware. Includes a US quarter coin in photos for scale reference.
• Complete Hardware Assembly: Features all four original top locking thumbscrews to secure the runners, plus the large master micrometer adjustment wheel along the lower track.
• Original Blue Steel Tension Spring: The highly critical tempered blue steel leaf spring is completely intact along the lower spine, maintaining uniform tension across the tool's pivoting arch.
• Prick-Point Steel Runners: Equipped with all four original adjustable steel runners featuring highly defined alignment tips and centering cones.
Condition Notes:
An exceptional specimen presenting a rich, deep untouched historic brass patina with light workshop oxidation spots. Mechanically complete; all screw threads turn smoothly and clamp firmly. An absolute center-piece asset for any antique tool collection, precision machinist display, or practicing master watch restorer's bench.