3. What is meant by silk reeling?
4. What can you say of the length of the silk fiber?
5. In what way does the silk fiber differ from the other fibers?
6. What is the chief characteristic of the silk fiber?
7. What are other characteristics of the silk fiber?
8. In what form is silk exported?
9. In what countries is most of the raw silk produced? (See _Textiles_, page 206.)
10. With what does the silk manufacture in the United States begin?
11. Who is the _throwster_ and what is his work?
=Experiment 12--Linen Fiber=
Apparatus: Microscope.
Material: Flax fibers.
Reference: _Textiles_, chapter xv, page 193.
_Directions_
1. The linen fiber is obtained from the flax plant. Certain fibers, such as flax, jute, and ramie, are obtained from the stem of the plant, hence are known as _bast_ fibers, and flax is the most important bast fiber.
2. It is difficult to separate the flax or linen fiber from the woody part of the stem. The process is called _retting_, which is really rotting by soaking the stem in water.
3. Before the fibers are entirely free from the woody part of the plant they undergo the processes of beating, breaking, scutching, hackling, etc.
4. Read the account of each process. See _Textiles_, pages 194, 195.
5. Measure and record the length of two linen fibers.
6. Test the strength by trying to break the fiber.
7. Test for elasticity.
8. What is the appearance of the linen fiber when held to the light?
9. What is the color of the fiber? What is the process called by which linen is whitened? (Bleaching.)
10. Examine the flax fibers under the microscope. Observe that the fibers look like long cylindrical tubes. Describe the appearance of linen fibers under the microscope.
11. The best flax is grown in Belgium and Ireland.
_Questions_
1. From what part of the plant are bast fibers obtained?
2. Name some bast fibers.
3. What is the most important bast fiber?
4. What is retting?
5. For what purpose is linen subjected to retting?
6. Through what five processes does the flax fiber pass before it is free?
7. Where is the best flax grown?
=Experiment 13--Carding=
Apparatus: A pair of hand cards.
Material: Small quantity of scoured wool.
References: _Textiles_, pages 39 and 50.
_Directions_
1. Examine the hand cards. Notice that there is a foundation of several layers of leather. Notice that this foundation is covered with staples of steel wire. Notice that the staples are shaped like the letter U with the points turned one way. The covering of the hand cards is called _card clothing_.
2. Hold one hand card in the left hand, face up, wires pointing to the left. Spread the wool over the pointed wires of this card.
3. Hold the other card in the right hand, face down, with the wires pointing to the right. Bring the pointed wires of this card down on the wool and drag it lightly through the wires of the other card.
Repeat several times.
4. You have been _carding_ wool. The sharp points have been tearing the wool apart or disentangling the fibers. Carding brushes the fibers out smooth and makes them somewhat parallel. It forms them into a thin sheet.
5. The wool must be carded many times before it is sufficiently disentangled for drawing and spinning. In order to card again the hand card must be _stripped_ of the wool so that it may be dragged again through the staples.
6. Hold the hand card, which is in your right hand, erect. Notice that the wires point downward. Move the other hand downward over the wires. Notice that the surface is smooth. The points do not prick as they will if you try to brush the hand upwards over the wires.
7. Hold the card in the left hand in a similar position. Raise and bring the sharp wires of this card down on the smooth surface of the other card and strip it of its wool.
8. Card again, then strip again. Repeat several times until the fibers are thoroughly disentangled.
9. This carding and stripping, once done by hand, is now done in the mill by a power machine called the _card_. (See picture, _Textiles_, page 38.) Notice that instead of cards this machine consists of rollers or cylinders. Some are carding cylinders and some are stripping cylinders. The principle is the same as that of the hand cards. The wool is carded and stripped again and again and is finally delivered in a soft, fluffy rope called a _sliver_ ready for drawing and spinning.
_Questions_
1. What is the covering of the hand card called?