| Year | 2000 |
| Date | 10-Mar |
| Volume | 184 |
| Issue | 4,115 |
| Page | 326 |
| Category | Optical |
| Part | 5 |
| Title | An Optical Comparator for the Home Workshop |
| Author | Richard E.Butterick (Canada) |
| Notes | Constructs the co-ordinate micrometer stage. Micrometers, extension rods, ball retainers |