| Year | 1921 |
| Date | 14-Jul |
| Volume | 45 |
| Issue | 1,055 |
| Page | 37 |
| Category | Radio Engineering |
| Part | |
| Title | The Thermagnion |
| Author | Captain H. de A.Donisthorpe |
| Notes | Simple wireless circuit, elevation & cross section of coil, curves illustrating the usual characteristic error, valve used in the experiment |