| Year | 1924 |
| Date | 15-May |
| Volume | 50 |
| Issue | 1,203 |
| Page | 542 |
| Category | Electrical |
| Part | 2 |
| Title | The "C.-H." Electrical Locks |
| Author | B.Clements-Henry |
| Notes | Detail of magnet and armature, winder and detail of bobbin insulation, terminal block and catch-piece details, framing, latch and link |