One globe showing the continents and seas and another showing the stars in the sky were part of the furniture in an 18th-century gentleman’s library. They were considered a sign of education, even if the owner knew little about their use.

By the 19th century, the study of the planets became part of the curriculum of most schools. Globes became commonplace.

The best tool for teaching astronomy was another model, the orrery. It showed the sun, Earth and planets and demonstrated their motions, although it was not made to scale.

The first orrery was made by clockmakers in the early 1700s. It was a decorative piece, not a scientific instrument. A crank made the Earth and moon revolve. A candle was used to represent the sun.

Some orreries had a brass ring with a graduated scale and a pointer that told the date. These rare, attractive instruments now sell for high prices to collectors and museums interested in the science of past centuries.

I have a cloth doll made from a printed pattern that was cut and stuffed. He is dressed in red-striped pants, a tux jacket and a hat marked “Uncle Sam.” It is old and about 7 inches tall. Can you tell me when it was made?

Uncle Sam was a popular symbol for the United States by the mid-19th century. Your doll might have been one of many “cut and sew” dolls made from the 1890s to the 1910s by Arnold Printworks of North Adams, Mass.

The firm made prints and dress goods and sold several doll sheets that customers could cut, stuff and sew. Most assembled cut-and-sew dolls from that era sell for $75 or more.

I have six 10-1/2-inch china plates that are souvenirs from the 1939 New York World’s Fair. The plates are blue and white and show different buildings at the fair. The words on the back of each plate begin with the name of the building pictured, such as “Textile Building.” The marking continues with: “New York World’s Fair, 1939, Abraham & Straus, Inc., Brooklyn, New York, 1st Edition, Copeland Spode, England.” Are the plates worth anything?

Copeland Spode of Stoke, Staffordshire, England, traces its history to at least 1847. The firm made hundreds of pieces of American souvenir china beginning in the 1930s. These souvenirs include your set of World’s Fair plates, as well as plates that picture views of colleges, cities and famous buildings. Your plates sell individually for $25 to $50.

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