This section is from the "A Complete Dictionary of Dry Goods" book, by George S. Cole. Also available from Amazon: A complete dictionary of dry goods and history of silk, cotton, linen, wool and other fibrous substances,: Including a full explanation of the modern processes ... together with various useful tables.
Bowing (Bo'-Ing). The old process of preparing the fur for the body of a felt hat. Usually about 3 ounces of fur was spread upon a platform of boards about 5 feet square, over which a large bow some 6 feet long, strung with catgut, was suspended. This bow was held in the left hand of the hatter, while with the right he tugged or twanged the string of the bow and made it vibrate upon the fur, and into it with great dexterity and the nicest judgment. This operation has always been considered a beautiful sight to a stranger, as the hatter goes on plucking the string, and the string playing upon the top of the fur which lies upon the left hand side of the platform. The fur touched by the string is made to fly from one side of the boards to the other with the greatest regularity. In this operation the different materials are tossed to-and-fro and mixed with a much greater regularity than if drawn by machinery. One half of the intended hat, called a bat, is bowed at a time, and both in nearly a triangular shape, which is pressed and gently rubbed with the hands backward and forward so as to create a friction on the surface fibers, thereby interlacing the outside filaments, by which means the safe-lifting of the two half-solidified portions of the future hat is secured. The one-half being laid upon the other they are joined together by overlapping two of the three sides, thereby giving to the intended hat the form and figure of a hollow cone, but so tender that none but an experienced hatter could handle it. This finishes the operation of "bowing," after which come felting and shaping, for descriptions of which processes. See Hats And Caps.