Right on Joe! And didja ever wonder about all the tall smokestacks? Musta
been where they hid the gauges.

Bob Swinney
"Joseph Gwinn" wrote in message
...
In article ,
"Leo Lichtman" wrote:

"Robert Swinney" wrote: AFAIK, the earliest ones were mercury columns
or
water columns. (clip)
^^^^^^^^^^^^^^^^^
Want to make yourself smile? Picture a water column attached to a steam
boiler at 150 psi.*
________________________
* Water column about 300 ft tall.

High-pressure steam only came (in the 1800s) after James Watt, who
abhored high-pressure steam because of the then considerable danger from
boiler explosions. It took a long time for steel quality and boiler
safety systems to mature enough that a 150 psi boiler was practical for
general use.