SILK 



5383 



SILO AND SILAGE 



moved by combing, and the straightened fibers 

 are run together until thread is formed. This 

 is the spun silk of commerce, which is used in 

 making silk yarns and for woof in certain 

 fabrics. 



Weaving. Silk is woven on looms similar to 

 those used for cotton and wool. Power looms 

 have now supplanted hand looms very largely, 

 but in China, where cheap labor prevails, weav- 

 ing is still a hand craft. In the manufacturing 

 of silk fabrics, France and the United States 

 take the lead. The first silk mill was set up at 

 Mansfield, Conn., in 1810. Power looms ap- 

 peared about 1838, and the weaving of silk fab- 

 rics spread throughout the Eastern states. Of 

 late years the growth has been exceedingly 

 rapid, the manufacture of finished products 

 ranking now among the country's great indus- 

 tries. In the United States there are 660 estab- 

 lishments producing finished silk products, em- 

 ploying nearly 90,000 persons. The capital in- 

 vested is about $140,000,000, and the value of 

 the product is $185,000,000 yearly. The indus- 

 try is concentrated in the East, the leading states 

 being New Jersey, Pennsylvania, New York, 

 Connecticut and Massachusetts. The manu- 

 facture of sewing silk is an important branch 

 of the industry in the United States. The 

 process of manufacture consists in doubling and 

 twisting the filaments together until a thread 

 of the desired size and strength is produced. 

 China furnishes an average of 20,000,000 pounds 

 of raw silk and 15,500,000 pounds of waste silk 

 to foreign manufacturers yearly. The exports 

 from Japan amount to nearly 30,000,000 pounds 

 a year. 



Artificial Silk. The great commercial value 

 of silk has naturally led to many attempts to 

 place a substitute on the market. Cotton and 

 the pulp of soft woods have been experimented 

 with. Cotton is carded and steeped in a mix- 

 ture of fifteen parts of nitric acid to eighty- 

 five parts of sulphuric acid until its color is 

 clear blue. It is then washed and dissolved in 

 a mixture of ether and alcohol, forming col- 

 lodion. The collodion is then fed between roll- 

 ers, which squeeze the liquid through small 

 tubes into nitric acid diluted with water. The 

 resulting fibers are wound upon reels, washed, 

 twisted, spun and dyed. The process for wood 

 fiber is similar. Though the cost of manufac- 

 ture is considerably less than that of natural 

 silk, artificial silk has not been extensively 

 used. G.B.D. 



Consult Posselt's Structure of Fibres, Yarns 

 and Fabrics. 



A Booklet on Silk 



Use two sheets of paper 9x12 inches, 

 or larger, and fold once, making eight 

 pages. 



Cover page Story of Silk in center ; 



name of school and pupil's name at 



bottom. 



Illustrations : Border of convention- 

 alized mulberry leaves (see page 



3996) ; several moths in flight. 

 Inside cover Blank. 

 Page three Essay, The Moth and Its 



Eggs. 

 Illustration : Spray of mulberry 



leaves with moth and eggs on 



leaves. 

 Page four Essay, The Worm and Its 



Cocoon. 

 Illustrations : Worms feeding on 



leaves ; a group of cocoons. 

 Page five Essay, The Making of Raw 



Silk (killing of grubs, loosening and 



winding of fiber). 

 Illustration : Hanks of raw silk. 

 Page six Essay, Silk Weaving. 



Illustration : Machine with silk 



wound upon it. 

 Page seven A page of original designs 



for silks, done in colors ; show 



stripes, plaids and figured patterns. 

 Page eight List of articles made from 



silk. 

 Illustrations : Articles made from 



silk, as ribbons, gloves, stockings, 



neckties, etc. 



Related Subjects. The reader may consult 

 the following articles in these volumes : 

 Adulteration of Food- Moth 



stuffs and Clothing Mulberry 

 Cocoon Weaving 



SILKWORM. See SILK, subhead The Silk- 

 worm. 



SILK 'WORM GUT, a substance made from 

 fiber drawn from a silkworm which was killed 

 at the time it was ready to spin. The thread, 

 after going through several interesting proc- 

 esses, is used to form the hook end of a fish- 

 line. It is first soaked in cold water and then 

 in a caustic solution. The outside covering is 

 then taken off and the thread is dried, and, if 

 desired, bleached white. A pound of gut can 

 be made from about 25,000 threads. Silkworm 

 gut is valued because it is strong and is invisi- 

 ble in water. 



SI'LO AND SILAGE, si' lay j. The word silo 

 is applied to a structure in which green crops 



