For more information on Calder and his art, click here.

The can opener was invented in 1858 by Ezra Warner of Waterbury, Connecticut, USA. Warner's device used a lever and chisel. Until then, cans were opened using a hammer and chisel; the can opener was invented 50 years after the metal can was invented.

The can opener was improved in 1870 by William Lyman of West Meridian, Connecticut, USA. Lyman's device used a rotating wheel and a sharp edge. His can opener only fit one size of can, and first had to pierce the center of the can.

The modern-day type of can opener (using a serrated wheel) was invented in 1925.

For more information (and activities) about caravels, click here.

In 1770, the Swedish chemist Torbern Bergman invented a device for making carbonated water from chalk and sulfuric acid.

Chester F. Carlson was born in Seattle, Washington, USA. As a teenager, Carlson supported his invalid parents by publishing a chemical journal. After attending Cal Tech in physics, Carlson worked at an electronics firm. Carlson later experimented at home to find an efficient way of copying pages. He succeeded in 1938, and marketed his revolutionary device to about 20 companies before he could interest any. The Haloid Company (later called the Xerox Corporation) marketed it, and photocopying eventually became common and inexpensive.

For more information on Carver, click here. For a cloze (fill-in-the-blank) activity on Carver, click here.

John H. Patterson (1844-1922) bought Ritty's patent and his cash register company in 1884. Patterson renamed the Dayton, Ohio, company the National Cash Register Company. Patterson improved Ritty's cash register by adding a paper tape that kept a printed record of all transactions.

In 1906, Charles F. Kettering (and employee of NCR) developed an electric cash register (Kettering later worked for General Motors and invented the electric car ignition).

The National Cash Register Company was later called NCR, until the company was bought by ATT in 1991; it was given back the name NCR in 1996, when it was split off from ATT.

When Atlanta banned alcohol consumption in 1885, Pemberton had to change the formula of his French Wine of Coca, omitting the French wine. He added sugar, citric acid and essential oils of many fruits to the drink, and the original Coca-Cola was created. It was named for its main ingredients, coca leaves and the kola nut. Coca-Cola quickly became a very popular soda fountain drink.

Pemberton became partners with Frank Robinson and David Roe, but the partners soon began to quarrel and Pemberton soon sold his interest in Coca-Cola. The formula for Coca-Cola is a closely-guarded secret.

Contact lenses were invented and made in 1887 by the German physiologist Adolf Eugen Fick (1829-1901). He first fitted animals with the lenses, and later made them for people. These lenses were made from heavy brown glass and were 18-21mm in diameter. The lenses were improved by August Muller in 1889; he made lenses that corrected myopia (nearsightedness).

Plastic contact lenses were first made by the California optician Kevin Tuohy in 1948. Soft contact lenses (hydrophilic lenses) and gas-permeable lenses (which let oxygen pass through the lens and to the cornea) were invented in the 1970s.

In 1795, the Nicholas Jacques Conte (a French officer in Napoleon's army) patented the modern method of kiln-firing powdered graphite with clay to make pencils of any desired hardness.

For a more on the invention of the pencil, click here.

The first upright piano was made around 1780 by Johann Schmidt of Salzburg, Austria. Thomas Loud of London developed an upright piano whose strings ran diagonally (in 1802), saving even more space.

For more information on George Crum and potato chips, click here.