The Steamboating Forum

Here is a twin that is on Craigslist in New York

http://newyork.craigslist.org/lgi/boa/2837726607.html

That's a Semple compound. 10hp 3&5x4" I believe. They utilize slip eccentric, though I know of one (John Nobel's Ranel II) that had been converted to Stephenson link, which made maneuvering much easier and more reliable.

Good engines.

That's a compound Semple But I have seen a picture of a Semple twin in the same "V" configuration -it was rated at 20 HP and must have used a lot of steam!