| Year | 1940 |
| Date | 10-Oct |
| Volume | 83 |
| Issue | 2,057 |
| Page | 280 |
| Category | Hot Air |
| Part | |
| Title | Practical Notes on Hot Air Engines |
| Author | "Artificer" |
| Notes | Advantages of hot-air engines, working parts of Heinrici engine with piston and displacer in correct relative position |