As used at Penrhyn Quarry. The patent appears to refer to the valve rather than the engine as a whole.
Copy & Paste Forum Code
To display this photograph in a forum message please copy the text below and paste it into your forum message:
[photo]117576[/photo]
To display this photograph in a forum message and link to the full size image please copy the text below and paste it into your forum message:
[link]117576[linkphoto]117576[/linkphoto][/link]