In the above expression R, π and L are constant, therefore as d increases the term (R − r) must decrease; this can happen only when r is increased, that is, when the bobbin revolves quicker. It is easy to see from the above expression that if the bobbin were the “leader” its speed would have to decrease as it filled.
The builder, which receives its motion from the disk and scroll, from the cones, or from the expanding pulley, has also an intermittingly variable speed. It begins at a maximum speed when the bobbin is empty, is constant for each layer, but decreases as the bobbin fills.
The rove yarn is now ready for the spinning frame, where a further draft of about eight is given. The principles of jute spinning are similar to those of dry spinning for flax. For very heavy jute yarns the spinning frame is not used—the desired amount of twist being given at the roving frame.
The count of jute yarn is based upon the weight in pounds of 14,400 yds., such length receiving the name of “spyndle.” The finest yarns weigh 2¾ ℔ to 3 ℔ per spyndle, but the commonest kinds are 7 ℔, 8 ℔, 9 ℔ and 10 ℔ per spyndle. The sizes rise in pounds up to about 20 ℔, then by 2 ℔ up to about 50 ℔ per spyndle, with much larger jumps above this weight. It is not uncommon to find 200 ℔ to 300 ℔ rove yarn, while the weight occasionally reaches 450 ℔ per spyndle. The different sizes of yarn are extensively used in a large variety of fabrics, sometimes alone, sometimes in conjunction with other fibres, e.g. with worsted in the various kinds of carpets, with cotton in tapestries and household cloths, with line and tow yarns for the same fabrics and for paddings, &c., and with wool for horse clothing. The yarns are capable of being dyed brilliant colours, but, unfortunately, the colours are not very fast to light. The fibre can also be prepared to imitate human hair with remarkable closeness, and advantage of this is largely taken in making stage wigs.
For detailed information regarding jute, the cloths made from it and the machinery used, see the following works: Watts’s Dictionary of the Economic Products of India; Royle’s Fibrous Plants of India; Sharp’s Flax, Tow and Jute Spinning; Leggatt’s Jute Spinning; Woodhouse and Milne’s Jute and Linen Weaving; and Woodhouse and Milne’s Textile Design: Pure and Applied.
(T. Wo.)
[1] Also in the forms “streek,” “strick” or “strike,” as in Chaucer, Cant. Tales, Prologue 676, where the Pardoner’s hair is compared with a “strike of flax.” The term is also used of a handful of hemp or other fibre, and is one of the many technical applications of “strike” or “streak,” which etymologically are cognate words.
JÜTERBOG, or Güterbog, a town of Germany in the Prussian province of Brandenburg, on the Nuthe, 39 m. S.W. of Berlin, at the junction of the main lines of railway from Berlin to Dresden and Leipzig. Pop. (1900), 7407. The town is surrounded by a medieval wall, with three gateways, and contains two Protestant churches, of which that of St Nicholas (14th century) is remarkable for its three fine aisles. There are also a Roman Catholic church, an old town-hall and a modern school. Jüterbog carries on weaving and spinning both of flax and wool, and trades in the produce of those manufactures and in cattle. Vines are cultivated in the neighbourhood. Jüterbog belonged in the later middle ages to the archbishopric of Magdeburg, passing to electoral Saxony in 1648, and to Prussia in 1815. It was here that a treaty over the succession to the duchy of Jülich was made in March 1611 between Saxony and Brandenburg, and here in November 1644 the Swedes defeated the Imperialists. Two miles S.W. of the town is the battlefield of Dennewitz where the Prussians defeated the French on the 6th of September 1813.