Below is explained how to make from 1-in. thick plates a wrought-iron cone of a rather pronounced slant. The lath being so great, the flange may be thrown oil, and the seating at the small end of the cone worked in after the cone has been bent to shape and the seams made. To cut the pattern for a cone made in this manner, first draw an elevation of a section through the centre as A B C D. Produce the sides of the cone, and make the length to A'B' equal to the length necessary for the flange, and also make the length to C equal to the length to be worked in to form the seating. Where the lines produced intersect at 0 is the apex of the cone. Use this as centre, and with the radius 0 A' draw an arc of a circle. Now divide the quarter circle 0' BE (usingO'B'as radius) into any convenient number of equal parts, and set off a corresponding number of similar divisions on the curve of the pattern, as A' 1. Now take the distance A' 1 and set off from I to give the point 2; if a line were drawn from 2 to the centre O this would give one-half of the pattern. If it is found convenient to cut the pattern in one piece, set off two other divisions as 3, 4. Join 4 to the centre 0, and then with 0 as centre and O C as radius, describe the arc of a circle shown to form the small end of the cone.

The cone could be partly bent to shape in the rollers, and then worked round true upon a mandrel. Braze the seams, and then throw off the flange with a stretching hammer, working it to an arc of a circle first upon the mandrel, and then working it down flat afterwards upon the flat end of the anvil. The small end could be set in by working overhand upon an upright circular stake with the edge bevelled off. First tuck the metal in round the edge with cross blows from the stretching hammer, then set it in on the shoulder or the head a short distance down from the part first tucked in. Now work from this furrow up to the top edge, beating the metal over while working upwards to form the shape required. Again tuck the metal in at the top, and repeat the process described above until the work is brought to the desired shape.

Pattern for Wrought-iron Cone.