| Year | 1991 |
| Date | 03-May |
| Volume | 166 |
| Issue | 3,896 |
| Page | 518 |
| Category | Workshop |
| Part | |
| Title | Optical Centre Punch/Radius Turning Tool |
| Author | Mark Salsbury (Australia) |
| Notes | The optical magnifier, the radius turning attachment, machining the lens, use of the centre-punch |