Chapter II.
Looms Should Be Adapted to Make a Wide Variety of Goods—Take-Up and Let-Off Motions—Making the Rubber Warps for Different Classes of Web—Importance of Uniform Tension—Defects from Uneven Tension and Chafing of Threads
The greatest care is necessary in planning out the details of the harness. On account of the great length it becomes necessary that everything possible be done to avoid any chance of warping or sagging, for the least irregularity which may be developed will of course interfere with the evenness of the shed. The harness frames must be made of the very best stock obtainable, thoroughly seasoned, and absolutely straight grained. Each frame must be supported at regular and frequent intervals by stays or supports mortised in the runners. These stays are slotted at top and bottom to receive the heddle bars and keep them accurately in line, and thus prevent them from catching on the neighboring harness during the operation of the shedding process.
It is necessary also that the top and bottom heddle bars be accurately spaced so as to allow proper freedom for the heddles to ride easily on the bars, and thus avoid any binding of heddles which would have a tendency to crowd the warp stock together and prevent clearance of the shed. Steel heddles are preferable to ones that bend and twist more or less and get out of alignment. They are made from tempered steel which is very flexible and they have round cornerless eyes that cannot possibly catch or chafe the warp threads. They adjust themselves automatically to the frame and cannot twist or bend while at work, and are made to accommodate themselves to every conceivable kind of goods.