| Year | 1999 |
| Date | 05-Nov |
| Volume | 183 |
| Issue | 4,106 |
| Page | 578 |
| Category | Stationary Engine |
| Part | 7 |
| Title | Harlequin & Hybriquin |
| Author | Mike Thurgood (South Africa) |
| Notes | Describes Corliss and drop valve variants. Valve design, design for a modified drop valve gear, cylinder assembly |