ferent directions
and notice that the cotton threads form the warp. Why?

Another way to tell the warp threads in a fabric is to examine warp
and filling threads very closely and notice which set contains the
greater twist? Why? See if they are separated at more regular
intervals. Why?

Stiffened or Starched Fabrics.--Examine stiffened or starched goods
very closely and notice the threads. If only one set can be seen they
are the warp threads. The stiffer and straighter threads are found in
the warp. Why? The rough and crooked threads are seen in the filling.

=Experiment 34--Determining the Density of a Fabric=

Apparatus: Pick glass.
Materials: Samples of cloth.
Reference: _Textiles_, page 238.

_Directions_

1. Examine different samples of cloth and determine the number of
filling threads and warp threads by means of a pick glass.

2. Then examine different priced fabrics of the same kind and see
whether the low or high priced fabric has the greater density.

=Experiment 35--Determining Weight=

Apparatus: Balances, die.
Materials: 4 square inches of cloth.
Reference: _Textiles_, page 239.

_Directions_

1. Fabrics are bought and sold by the yard. In order to express the
amount of wool or cotton in a fabric the weight in ounces per yard is
usually given.

2. In order to find the number of ounces per yard a piece of cloth of
definite size, usually about 4 sq. in., is stamped out by means of a
die, or cut by means of a tin plate exactly 4 sq. in. (2 in. on the
side). This is then weighed on very accurate balances and expressed in
grains. Find the weight per yard. Remember 7000 grains equal 1 lb.; 16
oz. equal 1 lb.

=Experiment 36--Determining Shrinkage=

Apparatus: Hot water.
Material: Sample of woolen fabric.
Reference: _Textiles_, page 239.

_Directions_

1. Take a sample of a woolen fabric 12 in. by 20 in. and pour hot
water over it and leave it immersed over night. Then dry it in the
morning at a moderate temperature without stretching. Then measure its
length and divide the difference in lengths by the original length.
The quotient multiplied by 100 will give the per cent of shrinkage.

2. Repeat the same experiment with a worsted fabric, and with a cotton
fabric.

3. Why does the woolen fabric shrink more than the worsted?

=Experiment 37--Test of Fastness[28] of Color under Washing=

Apparatus: Porcelain dish, soap solution. Materia