If I remember correctly, the mercury gauge on Stephenson's Rocket, was on
the outside of the stack!

Steve R.


"Robert Swinney" wrote in message
...
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.