Steam:
Its Generation and Use

ist. Sinuous headers for each vertical row of tubes. 2(1. A separate and independent con- nection with the drum, both front and rear, for WATER LINE mutally deteriorating strains where one was supported by the other, were avoided. Hundreds of thousands of horse-power of this style have been built in the last twelve years, giving excellent satisfaction. In fact, most of the boilers referred to in this book are of this style. It is still standard, and is known as our “C. I. F.” (cast-iron front) style, a fancy cast-iron front being generally used therewith, as shown in the perspective view. Recent investigations have shown that the average cost of up- keep of the boiler proper is less than five cents per horse-power per annum. No. 2i is a construction more popu- q lar in Europe, perhaps, where most of our boilers are made in this style. It is No. 20. known as our “ W. I. F.” style, the front each such vertical row of tubes. 3d. Ail joints usually supplied with it being largely made of between the parts of the boiler proper to be wrought-iron. In this boiler, flanged and made without bolts or screws-threads. surfaces to be used which require to be stayed. 5th. The boiler supported independently of the brick-work, so as to be free to expand and con- tract as it was heated and cooled. 6th. The drums not less than 30 in- ches in diameter, except for small boilers. 7th, Every part accessible for cleaning and repair. Having settled upon these points: No. 20 was designed having all these features, together with other improve- ments in the details of contraction. The general form of construction of No. 15 was adhered to, but short pieces of boiler tube were used as connections between the sections and drum, and mud-drum ; their ends being expanded into adjacent parts used ; the drum is longer, and the sections are connected to cross-boxes riveted to its bottom. Where hight is to be saved, the steam is taken with a Dudgeon expander. This boiler was also suspended entirely independent of the brick- work by means of columns and girders, and the out through an internal “dry pipe.” In this style also the drum is suspended from columns and girders, though not shown in the figure. No. 22, the last step in the develop- ment of the water-tube boiler, beyond which it seems almost impossible for science and skill to go, consists in mak- ing all parts of the boiler of wrought- steel, including the sinuous headers, the cross-boxes, and the nozzles on the drum. This was demanded to answer the laws of some of the Continental Nations, and the Babcock & Wilcox Co., have, at the present time, a plant turning out forgings as a regular business, which have been pronounced by the London Engineer to be “a perfect triumph of the forgers’ art.”