Antique WS Darley Mining Compass & Case w/ Instructions

This is a vintage W.S. Darley & Co. Dip Needle Surveying Compass, complete with its original case and instructions. The compass is in excellent condition, and the needle moves freely. The original chain is included. The instruction manual is in mint condition. This device measures earth's magnetic field intensity and can be used to locate buried pipes, water mains, or ore deposits. It features aluminum and brass ring construction with glass plates. The original black case has a snap closure. I have two of these available. Buyer must pick up from the Morton Grove Area. Cash only.