| Year | 1930 |
| Date | 06-Mar |
| Volume | 62 |
| Issue | 1,504 |
| Page | 227 |
| Category | Electrical |
| Part | |
| Title | Facts about Volt and Ampere Meters. Moving Coil Instruments |
| Author | G.Gentry |
| Notes | Moving-coil instruments, magnet poles, magnet field, one magnet in the field of another, concentrating polar field of magnet, effect on magnet placed in concentrated field, practical details of permanent magnet, winding direction of electro magnets, frame |