| Year | 1923 |
| Date | 11-Oct |
| Volume | 49 |
| Issue | 1,172 |
| Page | 406 |
| Category | Workshop Topics |
| Part | |
| Title | The Practical Details in Making a Spherical Variometer Inductance |
| Author | |
| Notes | General note, the design, the principle of a true variometer, relationship between a plain coil inductance and variometer, neutral and minimum positions of a variometer rotor, particulars of the actual variometer |