Steam:
Its Generation and Use

 CONSTRUCTION. This boiler is composed of lap-welded wrought iron tubes, placed in an inclined position and connected with each other, and with a horizontal steam and water drum, by vertical passages at each end, while a mud-drum connects the tubes at the rear and lowest point in the boiler. The end connections are in one piece for each vertical row of tubes, and are of such form that the tubes are “ staggered ” (or so placed that each horizontal row comes over the spaces in the previous row). The holes are accurately sized, made tapering, and the tubes fixed therein by an ex- pander. The sections thus formed’ are connect- ed with the drum, and with the mud-drum also by short tubes expanded into bored holes, doing' away with all bolts, and leaving a clear passage way between the several parts. The openings for cleaning oppo- site the end of each tube are closed by hand-hole plates, the joints of which are made in the most thor- ough manner, by milling the sur- faces to accurate metallic contact, and are held in place by wrought iron forged clamps and bolts. They are tested and made tight under a hydrostatic pressure of 300 pounds per square inch, iron to iron, and without rubber-packing, or other perishable substances. The steam and water drums are made of flange iron or steel, END VIEW Or HEADER. of extra thickness, and double riveted. I hey can be made for any desired working pressure, but are always tested at 150 pounds per square inch unless other-wise ordered. The mud-drums are of cast iron, as the best material to withstand corrosion, and are provided with ample means for cleaning. ERECTION. In erecting this boiler, it is suspended entirely independent of the brick-work, from wrought iron girders resting on iron columns. This avoids any straining of the boiler from unequal expan- sion between it and its enclosing walls, and per- mits the brick-work to be repaired or removed, if necessary, without in any way disturbing the PARTIAL VERTICAL SECTION. boiler. All the fixtures are extra heavy and of neat designs. OPERATION. The fire is made under the front and higher encl of the tubes, and the products of the com- bustion pass up between the tubes into a com- bustion chamber under the steam and water- drum ; from thence they pass down between the tubes, then once more up through the spaces between the tubes, and of! to the chimney. The * 35