10 Circular Saw In the late 18th century, Tabitha Babbitt lived in Massachusetts and worked as a weaver, but in 1810, she observed men cutting wood with a pit saw, which is a two-handled saw that requires two men to pull it back and forth. Though the saw is pulled both ways, it only cuts wood when it's pulled forward; the return stroke is useless. To Babbitt, that was wasted energy, so she created a prototype of the circular saw that would go on to be used in saw mills. She attached a circular blade to her spinning wheel so that every movement of the saw produced results.
9 Chocolate Chip Cookies One day in 1930, Ruth Wakefield was baking up a batch of Butter Drop Do cookies for her guests. The recipe called for melted chocolate, but Wakefield had run out of baker's chocolate. She took a Nestle chocolate bar, crumbled it into pieces and threw it into her batter, expecting the chocolate pieces to melt during baking. Instead, the chocolate held its shape, and the chocolate chip cookie was born.
8 Liquid Paper Bette Nesmith Graham was not a very good typist. One day, Graham watched workers painting a holiday display on a bank window. She noticed that when they made mistakes, they simply added another layer of paint to cover them up, and she thought she could apply that idea to her typing blunders. Using her blender, Graham mixed up a water-based tempera paint with dye that matched her company's stationary. She took it to work and, using a fine watercolor brush, she was able to quickly correct her errors. She received a patent in 1958.
7 The Compiler and COBOL Computer Language Admiral Grace Murray Hopper deserves credit for her role in the computer industry. Admiral Hopper joined the military in 1943 and was stationed at Harvard University, where she worked on IBM's Harvard Mark I computer, the first large-scale computer in the United States. She was the third person to program this computer, and she wrote a manual of operations that lit the path for those that followed her. In the 1950s, Admiral Hopper invented the compiler, which translates English commands into computer code. Admiral Hopper also oversaw the development of the Common Business-Oriented Language (COBOL), one of the first computer programming languages.
6 Colored Flare System Martha Coston was widowed in 1847, she was only 21 years old. Through her dead husband's notebooks when she found plans for a flare system that ships could use to communicate at night. Coston requested the system be tested, but it failed. Coston spent the next 10 years revising and perfecting her husband's design for a colored flare system. One night she took her children to see a fireworks display, and that's when she hit upon the idea of applying some pyrotechnic technology to her flare system. The flare system finally worked, and the U.S. Navy bought the rights. The Coston colored flare system was used extensively during the Civil War.
5 The Square-bottomed Paper Bag Margaret Knight realized that paper bags should have a square bottom; when weight was distributed across the base in this way, the bags could carry more things. In 1870, she created a wooden machine that would cut, fold and glue the square bottoms to paper bags. Knight was awarded more than 20 patents in her lifetime.
4 Dishwasher You might think that the first dishwasher was invented by someone who spent years washing dishes, bemoaning the wasted time and the dishpan hands. Actually, Josephine Cochrane, who received the patent for the first working dishwasher, didn't spend that much time washing dishes. The real impetus for her invention was frustration over her servants breaking her heirloom china after fancy dinners. Cochrane was a socialite who loved to entertain, but after her husband died in 1883, she was left with massive debt. Rather than selling off that beloved china, she focused on building a machine that would wash it properly. Initially, Cochrane sought appointments with large hotels and restaurants, selling them on the fact that the dishwasher could do the job they were paying several dozen employees to do. In time, however, more households acquired the device as greater numbers of women entered the workplace.
3 Windshield Wiper At the dawn of the 20th century, Mary Anderson went to New York City for the first time. She noticed that the driver had to stop the tram every few minutes to wipe the snow off his front window. At the time, all drivers had to do so; rain and snow were thought to be things drivers had to deal with, even though they resulted in poor visibility. When she returned home, Anderson developed a squeegee on a spindle that was attached to a handle on the inside of the vehicle. When the driver needed to clear the glass, he simply pulled on the handle and the squeegee wiped the precipitation from the windshield. Anderson received the patent for her device in 1903; just 10 years later, thousands of Americans owned a car with her invention.
2 Nystatin Rachel Fuller Brown and Elizabeth Lee Hazen worked for the New York State Department of Health in the 1940s, but Hazen was stationed in New York City and Brown was in Albany. In New York City, Hazen would test soil samples to see if any of the organisms within would respond to fungi. If there was activity, Hazen would mail the jar of soil to Brown, who would work to extract the agent in the soil that was causing the reaction. Once Brown had found the active ingredient, it went back in the mail to Hazen, who'd check it against the fungi again. If the organism killed the fungi, it would be evaluated for toxicity. Most of the samples proved too toxic for human use, but finally Brown and Hazen happened upon an effective fungus-killing drug in 1950. They named it Nystatin, after New York state. The medication, now sold under a variety of trade names, cures fungal infections that affect the skin, vagina and intestinal system.
1 Kevlar It was just supposed to be a temporary job. Stephanie Kwolek took a position at DuPont in 1946 so she could save enough money to go to medical school. In 1964, she was still there, researching how to turn polymers into extra strong synthetic fibers. Kwolek was working with polymers that had rod-like molecules that all lined up in one direction. These polymers were very difficult to dissolve into a solution that could be tested. She finally prepared such a solution with the rod-like molecules. Her next step was to run it through the spinneret, a machine that would produce the fibers. However, the spinneret operator almost refused to let Kwolek use the machine, so different was this solution from all the others before; he was convinced it would ruin the spinneret. Kwolek persisted, and after the spinneret had done its work, Kwolek had a fiber that was ounce-for-ounce as strong as steel. This material was dubbed Kevlar.
