John P,
Whilst the efficiency and safety stuff you trot out is perfectly correct, remarks of this nature hold no respect or indeed awe or recognition for the incredible steam technology of our immediate ancestors that built the physical and practical foundations of industry, public infrastructure and society that shapes our world today.
If Boulton and Watt had not provisioned industry with hitherto unimagined power and capability, our manufactures of today might still have the technology of the 18th century. If Parsons hadn't sought a more efficient use of steam from the reciprocating engines you deprecate, John P, we would never have had the steam turbine and therefore modern electricity generation and long distance shipping capabilities may never have come about.
The projects of restoration and reconstruction of our steam heritage that strong and dedicated men achieve (Like ReubenT) recognise and remember both the contribution of those 18th and 19th century engineers and the wonderful fascination that arises from the deployment of coal and water and iron in the creation of fire, steam, motion and naked power that is the soul of a steam engine whether it be a child's toy or a 3-storey steel mill rolling engine.
Had not cheap oil been discovered in the USA, the internal combustion engine arguably would never have gained the dirty, polluting stranglehold it has achieved of the world's mechanical power provision. Had the internal combustion engine not been invented then I am absolutely sure that our human ingenuity would have developed the steam engine into an efficient, streamlined, clean and universal source of all the same sorts of power. Turbines and rotatory units would have flourished and who knows, cleaner, greener cheaper electrical generation methods and traction may have been developed in the stead of being in the thrall of the finite resources of fossil fuel to which we have become so enamoured.
I am happy on this occasion to digress and topic-drift in celebration of steam - the true power - and to encourage reubenT's efforts with construction of one of these magnificent machines and to see if he might post the odd photo of his machinery and the progress of his project. It will not displace any of our naturism chat - merely add to it as Reuben will be occupied in his hobby as naked as possible, I am sure.
Hurrah for steam!
John
'A' Level Engineering grade B and erstwhile steam engine constructor at 1/8th scale! Also possessor of well-developed sense of humour