This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1899 edition. Excerpt: ...turned on the former for the back head. Turn the concave first as there will be a better chance to hold the plate upon the former. Figure 84 is a difficult piece of work, used to connect a "Belpair" fire-box to the barrel. Two formers were used for this; one for the hole, the other for the back side. The hole was flanged first. The former for the back had four lugs or brackets, cast upon its face, high enough to take full hold of the circular flange. These brackets served to steady the plate while the back flange was turned. Extra allowance of stock was necessary on the top and sides as those portions were drawn in by the flanging of the hole. Domes should be riveted up before flanging except that portion of the lap that comes in the flange, which must not be punched until afterwards. Make extra allowance of stock on the corners for drawing. A line of points should be made on the inside, similar to those in figure 81, as a guide. The barrel plate should be rolled up to shape and used as a former to fit the dome by. After the dome flange is fitted, it can be used in turn as a former for the barrel plate. VII. WELDING PLATES. To weld plates the greatest care should be taken to prepare the surfaces, as well as to get the proper heat. A perfect weld is flawless, the two parts being united equally throughout the length of contact, and they must be brought together before they will unite. All scale and cinder must be expelled. Scale, in the presence of a flux, and cinder, while hot, are fluid, and it is obvious that if the surfaces are concave or have concave spots, that when they are brought together, the sides of the cavities will unite and imprison them before there is a chance for them to escape, and no matter how hard the metal...