| Year | 1939 |
| Date | 30-Mar |
| Volume | 80 |
| Issue | 1,977 |
| Page | 370 |
| Category | Petrol Engine Topics |
| Part | |
| Title | Notes on Miniature Sparking Plugs |
| Author | Edgar T.Westbury |
| Notes | Spark gap design, materials for sparking plug insulators, porcelain, steatite, a typical amateur-constructed plug, mica, quartz, a manufacturing proposition, a mica centre plug, ready-made insulators, glass insulators, production difficulties |