In the section on Flat-Seam Roofing it was explained how a conical tower, Fig. 214, would be covered. It will be shown now how this tower would be covered with stand ing-seam roofing. As the circumference of the tower at the base is 396 inches, and assuming that x 20-inch tin plate is to be used at the base of the tower, the nearest width which can be employed and which will divide the base into equal spaces is 17 2" inches, without edges, thus dividing the cir cumference into 23 equal parts. Then the width of inches and the length of the rafter A B or A C in elevation will be the basis from which to construct the pattern for the standing seam strip, for which pro ceed as follows: Let A B C D in Fig. 228 represent a 20-inch wide strip locked and soldered to the required length. Through the center of the strip draw the line E F. Now measure the length of the rafter A B or A C in Fig. 214 and place it on the line E F in Fig. 228 as shown from H to F. At right angles to H F on either side draw F 0 and F L making each equal to 8i1 inches, being one half of the above referred to.
From points L and O draw lines to the apex H (shown broken). At right angles to H L and H O draw lines H P equal to 1} inches and H S equal to 1 inches respectively. In similar manner draw L D and
O C and connect by lines the points P D and S C. Then will P S C D be the pattern for the standing seam strip, of which 22 more will be required. When the strips are all cut out, use the roofing tongs and bend up the sides, after which they are laid on the tower, fastened with cleats, and double seamed with the hand reamer and mallet in the usual manner.
If the tower was done in copper or galva nized sheet iron or steel, where 8-foot sheets could be used, as many sheets would be cross locked together as required; then metal could he saved, and waste avoided, by cutting the sheets as shown in Fig. 229 in which A B C D shows the sheets of metal locked together, and F, and F the pattern sheets, the only waste be ing that shown by the shaded portion. Where the finial D in Fig. 214 sets over the tower, the standing seams are turned over flat as much as is required to receive the finial, or small notches would be cut into the base of the finial, to allow it to slip over the standing seams. Before closing the seams, they are painted with white lead with a tool brush, then closed up tight, which makes a good tight job.