=15. Sectional Sash Weights.=—There is a form of sash weight in the market known as the =Walda sectional weight=, which is illustrated in Fig. 11. This weight, as will be observed, is so arranged that units or sections may be detached or added, as desired, to diminish or to increase the weight. Such a weight can be nicely adjusted to counterbalance any sash, and has the advantage over the cast-iron weight in that each part is interchangeable and no mistake can be made in ordering, as the necessary weight for any sash can be made up on the site. TABLE V WEIGHT, DIAMETER, AND LENGTH OF SASH WEIGHTS ========+==========+======== Weight | Diameter | Length Pounds | Inches | Inches --------+----------+-------- 3 | 1⅜ | 8½ 3½ | 1⅜ | 9¾ 4 | 1⅜ | 11 4½ | 1⅜ | 12¼ 5 | 1½ | 12 5½ | 1½ | 12½ 6 | 1½ | 14 6½ | 1½ | 15 7 | 1½ | 16 7½ | 1½ | 17 8 | 1½ | 18 8½ | 1⅝ | 16½ 9 | 1⅝ | 17½ 9½ | 1⅝ | 18½ 10 | 1⅝ | 19½ 10½ | 1⅝ | 20½ 11 | 1⅝ | 21½ 11½ | 1¾ | 19 12 | 1¾ | 20 13 | 1¾ | 21½ 14 | 2 | 18 15 | 2 | 19 16 | 2 | 20¼ 17 | 2 | 21½ 18 | 2 | 22½ 19 | 2 | 23½ 20 | 2 | 24½ 21 | 2⅛ | 25 22 | 2¼ | 23 23 | 2¼ | 24 24 | 2¼ | 25 25 | 2¼ | 25½ 26 | 2¼ | 26 27 | 2¼ | 27 28 | 2¼ | 28 29 | 2¼ | 28½ ========+==========+======== FINISHING HARDWARE METALS AND THEIR MANIPULATION =16. Historical.=—From the days of Tubal-Cain, “an instructor of every artificer in brass and iron,” to the present time, no element in the world’s composition has rendered greater service in advancing man’s development than has the uninviting metal known as _iron_. Recent discoveries show the very ancient existence of iron in Assyria, and also in Egypt under the Pharaohs. It was found in considerable quantities in Syria, in Canaanite times, and many tools and implements of warfare were made from it. The Chalybes, located near the Black Sea, were in Biblical times considered famous workers in “northern iron,” while Damascus steel, for ages, has been justly celebrated. _Copper_ was well known to the Israelites and Egyptians before the Exodus, and for many years previous to that event the Egyptians obtained it from Arabia. It was also a native product of Palestine, and was very largely exported from Cyprus, whence its name.