| Year | 1937 |
| Date | 18-Mar |
| Volume | 76 |
| Issue | 1,871 |
| Page | 260 |
| Category | Tool-Room Topics |
| Part | |
| Title | Accurate Squares |
| Author | R.Hutcheson |
| Notes | Precision cylinder for use as a square, try-square incorporating the precision cylinder, set-up for grinding sides and base of precision cylinder, adjustable button-square, in use |