The boiler to develop 120 horse power and to work under a constant pressure varying from 125 to 150 lbs. to the square inch.
All rivets are to be 21⁄2 and 11⁄2 inch pitch. The pitch line of the rivets to be not nearer 11⁄8 inches to the edge of the sheet.
To be 8 lug plates for each boiler not less than 2 feet long, 8 inches wide, and one inch thick.
There shall be six 1 inch anchor rods running front to rear of each boiler, in the brick work.
These boilers and all their fronts, fittings and connections will be subject to the inspection of…………………
MARKS ON BOILER PLATES.
Something has been said under another heading of the nature and requisite quality of the materials entering into the structure of the boiler. Too much emphasis cannot be laid upon the necessity for the use of the very best iron and steel that can be manufactured, and the most skillful and thorough workmanship that can be performed in constructing the boiler.
It is becoming the practice, both for land and marine boilers, for boiler plate makers to furnish “test pieces” from each sheet or plate that goes into the construction of a boiler, and a sheet showing the tensile strength of each sheet or plate that enters into its make up.