| Year | 1930 |
| Date | 13-Nov |
| Volume | 63 |
| Issue | 1,540 |
| Page | 474 |
| Category | Electrical |
| Part | |
| Title | Improved Breaks for Spark Coils |
| Author | J.Pike |
| Notes | Magnetic and Motor-driven Mercury Jet Types. General arrangement and details, method of mounting, commutator, base, elevation, winding diagrams, general view, four pole motor |