Science Projects And Inventions

"The mechanism falls like thunder; the head flies off, blood spurts, the man is no more." Joseph-lgnace Guillotin, 1789 In 1789, at the start of the French Revolution, Joseph- Ignace Guillotin (1738-1814), a medical doctor of progressive views, proposed a thorough-going reform of the French penal system. Inspired by the humane and rational principles of the Enlightenment, Guillotin's proposals included a single method of execution to replace the messy horrors of breaking on the wheel and hanging by the neck. Guillotin's mechanism would prevent suffering, while making capital punishment more democratic; beheading was traditionally the punishment reserved for aristocrats— an efficient decapitation machine would spread that privilege to all classes. In 1791 the French National Assembly appointed a committee to push the project through. Although Guillotin was involved, the prime mover was Dr. Antoine Louis, Royal Physician and Secretary of the Academy of Surgery. The basic design adopted, with a more...

"[Developing an escape slide] is like trying to balance a sheet of plywood on the head of a pin." Mark Robertson, engineer If an airplane crashes, an exit strategy needs to be in place. In fact, aviation authority rules state that it must be possible to completely evacuate an airplane within ninety seconds, under conditions of pitch black darkness and with half the exits blocked. In 1965 Jack Grant, who was working at Quantas Airlines as a safety superintendent, invented a superior inflatable escape slide that could double up as a life raft in the event of a crash landing at sea. His design was tried and tested in Sydney, Australia, with great success. In the 1960s, aviation authorities suggested that inflatable slides would only be useful if they could be fully deployed within twenty-five seconds, in moderate weather. The slide met these requirements and was also light and compact; more...

"To err is human, but to really foul things up requires a computer." Farmers' Almanac An accomplished mathematician and mechanical engineer, Charles Babbage (1791-1871) combined these two disciplines to create a "difference engine" capable of solving polynomial functions without having to use unreliable, hand-calculated tables. Despite generous government funding, Babbage sadly never fully finished his difference engine and the project was abandoned in 1834. This did not stop Babbage from thinking about computing, however. In 1835 he released designs for his "analytical engine," a device similar to the difference engine but which, by using programmable punched cards, had many more potential functions than just calculating polynomials. The analytical engine was never built, although Babbage produced thousands of detailed diagrams. Using the lessons learned from the analytical engine, Babbage created a more efficient and smaller difference engine in 1849. Difference Engine No. 2 was not built until 1991, when the London more...

"The Sl is not static but evolves to match the world's increasingly demanding requirements." International Bureau of Weights and Measures Scientists and engineers constantly need to measure distances, masses, times, temperatures, densities, velocities, electrical currents, and so on. All these quantities are then expressed as a number, and this means that units are absolutely vital. The idea of implementing common bases for all the units began with the British Association for the Advancement of Science in 1874. They suggested the centimeter for length, the gram for weight, and the second for time, which was known as the C.G.S. sytem. Prefixes such as mega- and micro- could then be used to indicate decimal multiples and submultiples. Unfortunately, this C.G.S. system was rather inconvenient in the field of magnetism and electricity. In 1889 the Conference Generaledes Poidset Mesures decided that the meter, kilogram, and second (m.k.s.) might be more appropriate. In 1946 more...

"...every great captain... became lost at sea despite the best available charts and compasses." One way of calculating the difference between a longitude at sea and a known longitude (of Greenwich, say) was to ascertain the mean solar time on the ship, by astronomical observations, and compare it with the time at Greenwich. To this end a clock was needed that accurately kept Greenwich time despite being rocked back and forth by the ship. In 1714 the British government offered a £20,000 prize (about £1,000,000 today) to anyone who could find longitude at sea to an accuracy of 0.5 degrees. Yorkshireman John Harrison (1693-1776) decided that an accurate clock was the answer. He built his first marine chronometer in 1735. This spring-driven clock was regulated by two connected balances that oscillated in opposite directions, thus eliminating all the effects of the ship's motion. Intentional variations in the lengths of the more...

"I... did not invent the easy-open can end. What I did was develop a method of attach ing a tab." Ermal Fraze The canned drink is one of the most familiar and practical inventions of the twentieth century. Until Ermal Fraze (1913-1989) came along, the problem was how to open them. Before his ring pull, cans had to be opened with a "church key," a tool similar to a bottle opener but with a sharp point at either end. One end was used to make a hole in the top to drink from, and the other to make a smaller hole for air to enter, allowing the liquid inside to escape. Fraze struck upon the idea of the ring pull when he was at a picnic and had forgotten his church key. Like most people of*,that time, he was aware that it was easy to injure yourself while trying to more...

The decision of Yale graduate Eli Whitney (1765-1825) to leave his Massachusetts home in 1792 and seek employment in the southern state of Georgia would radically alter the course of American history. While working on a plantation, Whitney learned of the financial need to make cotton-picking more efficient than was possible by the labor-intensive method of manually removing seeds from the cotton bolls. Within months he had constructed a device that rapidly separated the cotton from the seeds by pulling it through hundreds of short wire hooks mounted on a revolving cylinder. This method allowed only the fiber to pass through narrow slots in the iron breastwork; the seeds were left behind. The beauty of the cotton gin (the name derived from the Southern pronunciation of engine) lay in its simplicity of use, whether powered by man, animal, or water. Aware of the huge demand from English textile factories, Whitney more...

Measuring the distance between two places is a basic task in cartography. The earliest method was to walk and count the number of times a specific foot hit the ground—a thousand right steps, for example, made a mile (from the Latin "mille," meaning one thousand). The Roman architect and engineer, Vitruvius (c. 75 B.C.E.-c. 15 B.C.E.), mechanized the process. Around 27 B.C.E. he devised a wheelbarrow-type device that dropped a pebble into a container every time its large wheel of known circumference rotated once. At first this was pushed along by hand, but it was soon incorporated into a chariot, the standard chariot wheel being 4feet (1.2 m) in diameter. This wheel turned 400 times in a Roman mile. Needless to say, the smoothness of the road was important. The device was described by Hero of Alexander in chapter thirty-four of his book Dioptra.              more...

“... with one distillation it gives a clear colorless liquid of brilliant illuminating power." Lyon Playfair in a letter to James Young In 1848 Scottish chemist James Young (1811-1883) spotted the potential of a natural oil seepage at a Derbyshire colliery. By 1850 he had taken out a patent for a process of extracting crude oil from cannel coal. Young located a huge new source of coal, at Boghead Colliery in Bathgate, West Lothian, and in 1851 he built the world's first commercial oil refinery on the site. Young began a major industry that was to continue in full production for another fifty years, until the arrival of crude oil from the United States and the Middle East. Young's Paraffin Light and Mineral Oil Company sold paraffin oil and lamps and also produced naphtha, gas, coke, and ammonium sulfate. "Paraffin" Young, as he had become known, took out a U.S. more...

Before the Fourdrinier machine, paper was made one sheet at a time using a screen-bottomed frame and a mold, or vat, of wet pulp. Lifting the frame through the pulp allowed the water to drain, leaving pulp on the screen. The pulp layer was then pressed and dried. The size of a single shaet was restricted to how large a frame could be handled manually. Paper production was a skilled affair undertaken by craftsmen, often working in guilds. But by the eighteenth century, an increased demand for paper, and a desire to circumvent the paper makers' guild, prompted Frenchman Nicholas-Louis Robert (1761- 1828) to design a machine that would automate the process and produce a seamless length of paper, via a continuous belt of cloth-covered, wire-mesh screen. After much experimentation and testing, Robert's machine received a French patent in January 1799, but the design still needed development. The political situation more...