324 (#420) ############################################ CHAPTER XV DEFECTS IN RAW MATERIALS, TOPS AND YARNS DEFECTS in textile materials may be due to (a) The materials employed ; (6) The machines employed; and (c) The workers. In the following treatment the commoner defects coming under each of the above headings are briefly referred to. (a) The Materials Employed :- I. Lack of lustre due to the employment of a demi-lustre wool in place of a lustre wool; or of a lustre wool and mohair yarn in place of a pure mohair yarn. 2. Lack of strength due to the employment of wool with a weak staple. One year all the wool in Yorkshire had a weak place about half-way down the staple. 3. Lack of felting or milling property. Certain Cape and other wools markedly lack milling property. Fibres such as the Ovibos fibre lack this altogether. 4. Lack of fullness or "lift.” English wools “ are markedly different from Colonial cross- breds in this respect. Peruvian wools grown at a great height (14,000 ft.) tend to develop the English Down characteristic, -- - 324