Cocoonry Building, Photograph, Prince William County, circa 1900

Silk has been produced and sold as a consumer good for thousands of years. The origin of silk production was in China and the earliest known examples date to 3000 B.C.E. For centuries, the trade routes known as the Silk Road stretched beween Europe and East Asia. The Chinese kept their manufacturing process a closely guarded secret, but eventually silkworm cocoons and seeds for mulberry trees (the food source for silkworms) were smuggled to other parts of Asia and to Europe, where manufacturers in areas of France and Italy became the leading producers of silk in Europe. Later, large groups of skilled Flemish and French weavers fled to England as a result of  religious persecution, and an industrial complex for silk weaving developed in the 1620s at Spitalfields near London.

Producing silk is complex and requires specialized skills. The silkworm moth (Bombyx mori) has been domesticated for centuries. The result is a creature which is bred and raised on farms with wings too weak to fly and legs unable to crawl more than a foot or so. Silkworms are totally reliant on humans and are very labor-intensive, as they require specific dietary and habitat conditions to thrive. Silkworm larvae begin eating as soon as they emerge. They molt or shed their skin four times and become larger each time they molt. The larvae will grow up to 10,000 times their weight as they eat mulberry leaves almost continually soon after they hatch. Once the silkworms stop eating, their human caretakers build specially constructed frames which provide support and protection for the valuable cocoons. The cocoons are produced when the worm’s silk glands are fully developed, and they begin to secrete a sticky substance called sericin along with the silk threads. The silk threads harden in the air as the larva moves its head in a figure eight pattern. After the larva creates a support for a cocoon, it spins a cocoon from a single, continuous thread of silk which can be over a mile long. The process of spinning a cocoon can take two days to complete. The worm then enters its pupa stage, which, if allowed to continue, will result in an adult moth in about three weeks. Most of the insects, however, are killed with heat in the pupae stage, as they damage the cocoon when they emerge as adults and the heat does not damage the silk. 

Given the popularity of silk in England and the development of silk production in Europe, King James I and others encouraged silk production in Virginia in the 17^th century. The specialized labor force required, the limited diet of the silkworm (the larvae did not like the native mulberry trees), and the development of tobacco as a more successful cash crop ensured sericulture's failure in the colony. However, small scale silk manufacturing had a resurgence in the 19^th century and early in the 20^th century in Virginia.  The cocoonry building seen in the photograph is an example of the silk industry in Prince William County. The building likely dates back to an earlier time period and was probably no longer used to raise silkworms when the photograph was taken. However, it is one of the few remaining structures attributed to the silk industry in Virginia. Today, most silk is produced in China, Japan, or Korea, with small quantities harvested in Russia and other countries. 

Citation:  Cocoonry, Mountain View, 1900, Virginia W.P.A Historical Inventory Project, Library of Virginia. 

History: VS.1, VS.2 VS.3, VS.4, USI.1, USI.2, USI.3, USI.4, WHII.4, VUS.1, VUS.2, VUS.3

Science: 3.5, 4.5, BIO.7, BIO.8, ES.6, ES.8

Preview Activity 

Look at It: Look at the photograph, what might the building have been used for? Why do you think this? 

Post Activities

STEM STAT: English colonists at Jamestown attempted to raise silkworms but found the silkworms to be demanding as they required Asian mulberries and special living conditions to thrive. They also did not handle the heat and humidity of the Tidewater region well. How did the attempts at raising silkworms change the environment? Why might the environment and technological advancements in building design allowed for more success with silkworms in northern Virginia in the 19^th century?

Think About It: Consider the challenges in raising silkworms and producing silk. Why do you think the English persisted in their quest to raise silkworms despite the odds? 

Another Perspective: Silk was an expensive and popular material in England. Although there was a means to produce silk products in England and Europe, why would the English want to attempt to produce it in the New World? Consider the challenges of raising silkworms and the climate in England.