This section is from the book "Scientific Sewing And Garment Cutting", by Antoinette Van Hoesen Wakeman. Also available from Amazon: Scientific Sewing And Garment Cutting: For Use In Schools And In The Home.
Silk is not only a very beautiful, but a very wonderful fiber, for it is made either by insects or worms. There are many insects that make themselves little houses out of silk spun from their bodies. The webs and nests of spiders are of silk.
The silk fiber from which fabrics are made is spun by the mulberry silkworm, and beautiful cloth was first made from it by the Chinese, farther back than we have record of. They did not want anybody to know their art; and they kept it such a secret that every one supposed that the cloth was made from some kind of a plant, like flax or cotton. At last a traveler, about the year 550 A.D., found out the secret, and brought away some eggs of the silkworm in a hollow bamboo cane. These eggs were hatched, and in this way silk culture became known to all the world.
The famous writer and Greek philosopher, Aristotle, in speaking of the silkworm, says that it is "a great worm that has horns, and so differs from other worms."1 This big worm, when it is full grown, first spins a web about itself of finest fiber, often four thousand yards in length. The worm moves as it spins, in such a way that the fiber is wound round and round as regularly as thread is wound onto a spool. In three days the house of silk is complete. Then the worm lies still until it becomes a moth, which is similar to a butterfly. This moth moistens the silk house, which is called a cocoon, and makes its way out. Very soon after the moth leaves the cocoon it begins to lay eggs, and in three or four days has laid from four hundred to seven hundred.
1 Ask the children if they think that Aristotle was correct in saying that other worms have not horns.
The eggs of the silk-moth are carefully put into trays, and kept where the temperature does not vary, being neither too warm nor too cold; and soon the little worms begin to hatch. A paper punctured full of small holes is laid over the trays, in order that the worms may crawl through these holes. In this way fragments of shell, which adhere to them and would kill them, are scraped off.
As soon as the silkworms are freed from their shells, they begin to eat, and they do nothing else all day. Their food is mulberry leaves, and the worms hatched from an ounce of eggs will eat a ton of leaves in a month. The worms change their coats almost every week. At the end of a month they are full grown. They then creep up on branches provided for them, and begin to spin silk houses for themselves, in which they become moths. Only a few of these moths are permitted to live, and eat their way out of the cocoon, for that injures the silk. Enough to lay eggs are left on the branches; the others are removed and killed by baking the cocoons in an oven, exposing them to the hot rays of the sun, or shutting them up in a close room where charcoal is burning.
It is a great deal of work to care for silkworms, and where labor is valuable they are not very profitable. Then, too, they require so much to eat that they can only be successfully cultivated where there are great plantations of mulberry-trees.
Silkworm, Cocoon, and Moth.
The silk which the worm has spun is as fine as the web of a spider before it is unwound. The cocoons are assorted, and those of similar color are placed together. When this has been done, they are put into tepid water. If the water is too cold, the gum of the cocoon will not soften enough to permit the fiber to unwind well; and if it is too warm, it will sink to the bottom. Girls who are experts stir the cocoons until they soften, and the end of the fiber is found.
A number of these delicate silk fibers are put together through an eyelet, and after being crossed and twisted are wound on a reel. When these threads are dried, they cling together, and form a compact fiber of raw silk.
From the reels, this silk fiber is wound upon bobbins in such a way that the threads are all in diagonal lines. These bobbins are next placed on the spinning-frame and slightly twisted. Then these strands are cleansed, wound together upon a reel, and twisted into one thread.
The thread is then reeled into big skeins; and as it is moist, it must be thoroughly dried, thus making it ready to be sold to manufacturers by the pound. As these skeins are somewhat stiff, they are whirled about in hot soap and water to make them flexible. They are then dried, packed into linen bags, boiled in water, and again dried. The silk is now white and soft, and is ready to be sent away to be colored, and woven into ribbons or some of the many different kinds of beautiful silk cloth.
Reels and Skeins of Silk.
Spun silk is made of the waste silk and poor cocoons. It is not reeled, but is separated by machinery into strands about a foot long. These are spun together as cotton is, and made into yarn called spun silk, which is by no means as durable as the other kinds of silk.
There are over two hundred silk mills in this country; but most of the silk used here is brought from China, as there are not many silkworms raised in the United States.