Hi Jim
On (01 Sep 97) Jim Dunmyer wrote to Alec Cameron...
 JD> The very first steam engines worked on atmospheric pressure. Steam was
 JD> injected into the cylinder to displace the air, then water was injected 
to
 JD> condense the steam. The resulting vacuum caused the atmospheric pressure
 JD> on the other side to push the piston through its stroke. These were
 JD> walking beam engines, used to pump water from coal mines in England. No
 JD> crankshaft or other rotating nonsense. :-)
Thanks for the reminder. Then there was the "man machine" which had a 
ertical
"piston rod" longer than 100 feet. The rod passed vertically down the pit
shaft, with step brackets at intervals. The miners would ride it to and from
the gallery they worked in, stepping on and off at top dead centre and at
bottom dead centre, waiting briefly at each gallery for the rod to make one
pass, then step on it for transit to another gallery, and another, and so
on.
Unhurried days!  Cheers....ALEC
... ........The best carpenters make the least chips
--- PPoint 1.92
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