| Year | 1921 |
| Date | 02-Jun |
| Volume | 44 |
| Issue | 1,049 |
| Page | 429 |
| Category | Workshop |
| Part | 4 |
| Title | Precision |
| Author | |
| Notes | Some Tool-makers' Dodges. Methods of clamping rectangular and circular objects with one screw, case-hardening composition, a Bebel disc or tangent protractor, adjustable taper gauge, measuring diameters and angles |