Hi Bob,
That's a ripper.
One of my goals was to fit my old boat with a steam engine.
At the boat shed I moored my boat there was a.steam boat there similar to the one you posted.
I got to talk to the owner.
He built the motor himself...
His problem was getting good coal.
By the time I finished talking to him I felt I had learn all there was to selecting good coal.
He would go out in in and always blew his whistle...so cool.
After talking to him I realised steam and drift wood was never going to happen.
An easy way to describe a steam reciprocating engine [as opposed to a steam turbine] is that it is basically the same sequence of events that takes place
within a petrol or diesel engine, except that it is the power contained
within the steam that pushes the piston along the cylinder[s], and not
the expansion of an ignited fuel. The more pressure in the boiler, the more
power in the steam.
raymo
I asked because I was not sure.
I thought the first ones worked by cooling the steam such that the steam condensed the volume and the piston moved by being "sucked" rather than pushed.
Alex
From about 1760 onward there were numerous attempts to utilise
steam power, some quite practical, and others just fanciful. The
method you describe was soon abandoned as impractical. The true
beauty of steam power, is that like electric motors, it can exert full
power whilst stationary, unlike internal combustion engines which
exert more power and torque as their revs rise.
raymo
Beam engines to pump out mines were powered by condensing steam.
The steam filled the space above the piston then cold water was sprayed into the space which produced a vacuum pulling the piston up.
The action was not translated into a circular motion. It just went up and down.
The dual action piston used live steam injected into a cylinder by a shuttle valve operated by the cam rod. A much better use of the steam.
By the time it got to ships it evolved into the triple expansion engine where the steam when exhausted from the small piston powered the next larger cylinder and so on.
The sizes of the piston meant the steam did equal work in each cylinder.
Thank you Jennifer and Raymo
I was thinking of the importance of steam.
When one mentions steam power most folk think its the power of years gone by, however when you think about it it is still at the heart of many power generating system today.
Coal powered plants or NP plants still fundamentally are steam power.
Splendid pics of the York museum. 
