| Year | 1956 |
| Date | 26-Apr |
| Volume | 114 |
| Issue | 2,866 |
| Page | 682 |
| Category | Electrical |
| Part | |
| Title | Choosing electrical contacts |
| Author | Richard H.Mapplebeck |
| Notes | Advice on choosing the right material. "Oak" switch, spark quench, high speed relay, speed of make and break, shape of surface, rhodium-plated contacts, common contact metals, Vickers hardness values |