fire-bricks and fire-clay, the replacing and keeping in order of this being in some Steam Fire-Engines a fruitful source of annoyance.
The working steam pressure of Shand, Mason and Co.’s Engines in the Metropolitan Fire Brigade is 100 lbs. on the square inch, and the safety valves are constructed so that the man in charge cannot exceed this; but the boilers are proved to 300 lbs., and the engines may be worked with the greatest safety at a pressure of 150 lbs. on the square inch.
