| Year | 2005 |
| Date | 07-Jan |
| Volume | 194 |
| Issue | 4,238 |
| Page | 23 |
| Category | General |
| Part | 3 |
| Title | Paradoxical Gears (A new challenge; Intriguing Object) |
| Author | Jacques Maurel (France) |
| Notes | Making a demonstration set. Procedure, setting up, observations, new question |