| Year | 1951 |
| Date | 19-Jul |
| Volume | 105 |
| Issue | 2,617 |
| Page | 92 |
| Category | Historic |
| Part | |
| Title | "That Wonderful Year" |
| Author | "The Dominie" |
| Notes | John Penn's trunk-type marine engine, Penn's oscillating engine, William McNaught's compounding arrangement, the disc engine improved by Bishopp and built by Rennie invented by Taylor and Davies, Rennie's four-cylinder screw engine |