| Year | 1921 |
| Date | 29-Sep |
| Volume | 45 |
| Issue | 1,066 |
| Page | 257 |
| Category | Horology |
| Part | 2 |
| Title | A Spring-Driven Clock Electrically Wound |
| Author | F.Booker |
| Notes | The motor (general view), the commutator (twelve segment), constructing the rotating magnets or armature, bottom bearing plate, the commutator or circuit maker and breaker, elevations, side view, top bearing plate |