r picking, the
cotton is sent to the ginning factory to have the seed removed. It is
then pressed into bales by hydraulic presses, five hundred pounds being
the standard bale in the United States.

[Illustration: COTTON BALES]

[Sidenote: Physical Characteristics]

Purified bleached cotton is nearly pure cellulose. It resists the action
of alkalis well, but is harmed by hot, strong acids, or if acid is
allowed to dry on the fabric. It is not harmed by high temperature, and
so may be ironed with a hot iron.

[Illustration: WOOL FIBER AND SUBSTITUTES

1. South American Wool; 2. Noil from the Same; 3. Tangled Waste; 4.
Waste Combed Out; 5. Lap Waste; 6. Shoddy.]

WOOL

[Sidenote: Character of Fiber]

Wool is the most important animal fiber. Strictly speaking the name
applies only to the hairy covering of sheep, but the hair of certain
goats and of camels is generally classified under the same terms. The
wool fiber is distinguished by its scale-like surface which gives it its
felting and spinning properties. Hair as distinguished from wool has
little or no scaly structure being in general a smooth filament with no
felting properties and spinning only with great difficulty. Fur is the
undergrowth found on most fur-bearing animals and has in a modified way
the scaly structure and felting properties of wool.

[Illustration: MICROSCOPIC APPEARANCE OF WOOL FIBERS]

[Sidenote: Value for Clothing]

The great value of wool as a fiber lies in the fact that it is strong,
elastic, soft, very susceptible to dye stuffs and being woven, furnishes
a great number of air spaces, rendering clothing made from it very warm
and light.

[Sidenote: Quality of Wool]

Climate, breed, and food influence the quality of the wool. Where the
pasturage is barren and rocky, the wool is apt to be coarse.

[Illustration: MERINO RAMS

The Variety of Sheep Giving the Finest Wool.]

[Sidenote: Varieties of Sheep]

There are supposed to be about thirty distinct varieties of sheep,
nearly half of which are natives of Asia, one-third of Africa, and only
four coming from Europe, and two from America. Wool is divided into two
general classes--long and short staple, according to the average length
of fiber. The long fiber wool is commonly carded, combed and spun into
_worsted_ yarn. The short fiber is usually carded and spun into woolen
yarn. The short fiber obtained in combing long staple wool is called
"noil." It is used for