I recently acquired an Ashcroft, German-style, diaphragm gauge that is installed in a metal box. When I received it, I discovered that the well-worn label in the cover of the box described it as a “Test Instrument or Changeover Device of Elesco Exhaust Steam Injectors.” I then located a reasonably priced copy of the instruction manual for the device at an on-line bookseller. After ordering the book, I received a note saying that it had been lost, and refunding my money. There is another copy available, but it is priced at much more than what I paid for the gauge.
Does anyone here have a simple explanation of how this device was used?
(In the early 1850s, a company in Cincinnati was making German-style diaphragm gauges for use on locomotives. I don't believe that many gauges of this design have been manufactured in the last 70 years. Not many were used for steam service since the late 1800s.)
Bruce E. Babcock
