Glass Cutter: Monce's Hardened Steel Wheel

S. G. Monce's glass cutter (US 91,150, 1869): a small hardened steel wheel, bevelled from both sides to a sharp edge, turning on its own journals in a riveted frame on a handle. Drawn across the glass under pressure it rolls and scores a fine line like a diamond's, for a tenth of a diamond's cost, and it needs less skill. It is the wheel cutter still used today. The patent gives no sizes, steel grade or hardening method. The picture: the patent's drawing sheet.