Page:Steamlocomotivec00ahrorich.djvu/137

 being lightly riveted over and “caulked” with a light tool which has a circular head. The principal trouble, however, is with broken stays. This

Tubes. The chief defects of steel tubes are (1) pitting of the outsides due to the same cause as pitting of the boiler plates, and more particularly (2) leakage at the firebox tube-plate. In former years leakages were stopped temporarily by driving a conical tool, known as a “drift,” into the open firebox-end of the tube. This forced the metal of the tube against the walls of the tube-holes, but was very injurious to the tubeplate, and its use is now forbidden. Instead,