| Year | 1998 |
| Date | 28-Aug |
| Volume | 181 |
| Issue | 4,075 |
| Page | 258 |
| Category | Hot Air |
| Part | 4 |
| Title | Little Gem. A Twin Cylinder Hot Air Engine |
| Author | Ray McMahon (Northern Ireland |
| Notes | Describes the power and displacer pistons, crankshaft. Piston and fork, balance weights |