Archives October 2013

"Those who admire modem civilization usually identify it with the steam engine..." George Bernard Shaw, playwright and writer Thomas Newcomen (1663-1729), a Devonshire blacksmith, developed the first successful steam engine in the world and used it to pump water from mines. His engine was a development of the thermic syphon built by Thomas Savery, whose surface condensation patents blocked his own designs. Newcomen's engine allowed steam to condense inside a water-cooled cylinder, the vacuum produced by this condensation being used to draw down a tightly fitting piston that was connected by chains to one end of a huge, wooden, centrally pivoted beam. The other end of the beam was attached by chains to a pump at the bottom of the mine. The whole system was run safely at near atmospheric pressure, the weight of the atmosphere being used to depress the piston into the evacuated cylinder. Newcomen's first atmospheric steam more...

How often have you been listening to your favorite radio station in your car, only to have it slowly dwindle away as you drive out of range of the transmitter? The answer to this problem came in 2001 when a new way to receive radio made its debut—a national service beamed from outer space that, in return for a  subscription fee, offered 100 different channels, none of which would be interrupted by poor reception. The coverage, provided by two or three high-orbit satellites, came as a strong signal requiring no satellite dish, just an antenna the size of a matchbox. Although the broadcast could be dampened by skyscrapers or long tunnels, the signal was bolstered by transmissions from ground-based towers. Two companies were originally granted licenses to provide satellite radio in 1997: XM and Sirius, with XM getting off the mark first in the U.S. in September 2001 and Sirius more...

"The longer we were in it, the smaller it seemed to get..." William Beebe, deep-sea explorer Otis Barton's (1899-1992) famous marine exploration vehicle was reminiscent of a naval mine. A simple sphere made of steel, it once dangled from a 2-mile (3.5 km) cable deep into the ocean. Unlike a mine, however, the bathysphere was intended to hold two intrepid explorers, and at less than 5 feet (1.5 m) across, it was not exactly designed for comfort. In 1928, Barton was just a student, but his blueprint for the bathysphere caught the attention of scientist and explorer William Beebe (1877-1962). A collector of rare species, Beebe had already consulted several professional engineers about building a deep-sea diving vessel. He was impressed by Barton's design and started making plans for a test dive. The secret to the bathysphere's success was its simplicity—its spherical form meant that pressure was evenly distributed across more...

"A weak mind is like a microscope, which magnifies trifling things, but cannot receive great ones" Lord Chesterfield, English aristocrat The first microscopes were made around 1590 by the father and son team of Hans and Zacharias Jansen. These   Dutch   spectacle-makers fashioned   a microscope with a magnification of just twenty times. In 1673 Dutch Antony van Leeuwenhoek discovered bacteria (animacules), blood cells, protozoa, and spermatozoa with a microscope that magnified objects by 300 times. By 1886 Ernst Abbe had advanced the technique quite considerably, and his microscope reached the limits of resolution with visible light— about 2,000 angstroms, or 0.0002 millimeters. But to get better resolution you need something with a smaller wavelength. Ernst Ruska (1906-1988) and his professor, Max Knoll (1897-1969), realized that if electrons were accelerated in a vacuum, their wavelength could be one hundred thousandths that of visible light. These electron beams could then more...

A monorail replaces the more usual two-rail transport system with a single track, and its vehicles either straddle the rail or hang from it. In the first type, the pillars supporting the rail can be of different heights, and so rough terrain can be crossed cheaply. In the second type the rail can be suspended above canals and rivers, taking up little valuable land. In June 1825 Henry Robinson Palmer (1795-1844) opened a suspended monorail in Cheshunt, near London. Although designed to carry bricks, it could also carry passengers. For the United States Centennial Exposition of 1876, General Le-Roy Stone built a demonstration pillar monorail in Philadelphia. Other pillar monorail systems were built to carry agricultural products and mineral ores. The most famous passenger-carrying pillar monorail was the Irish 9-mile (14.5 km) Listowel and Ballybunion railway that ran from 1888 to 1924. A German suspended monorail in Wuppertal started service more...

"If you die in an elevator, be sure to push the Up button" Sam Levenson, American author and humorist Who would now dare to travel in a high-rise elevator if their life literally hung by the elevator cable? In 1852 Maize and Burns, a bedstead-making firm in Yonkers, New York, was faced with that problem— how to hoist its bedsteads up to the top floor of its premises without risk of them crashing down if the rope broke. Elisha Otis (1811-1861), the firm's master mechanic, had experience of designing safety brakes for railway wagons. He devised a system involving a platform that could move freely within an elevator shaft unless there was a cable failure, whereupon a tough steel-wagon spring would mesh with a ratchet in such a way as to catch and hold the heavy platform. Otis left the company to market his invention. Interest was slow at first, more...

"All the learnin' my father paid for was a bit O' birch at one end and an alphabet at the other." George Eliot, author In 1999, Yale Egyptologist John Darnell revealed to the world that the 4,000-year-old graffiti he had discovered at Wadi el Hoi in Egypt's western desert represented humankind's oldest phonetic alphabet. Incorporating elements of earlier hieroglyphs and later Semitic letters, Darnell's discovery contradicted the long-held belief that alphabetic writing originated in the area of Canaan (modern-day Israel and the West Bank) midway through the second millennium B.C.E. Nevertheless, the writings—carved into soft limestone cliff—are thought to be the work of Canaanites, or rather Semitic-speaking mercenaries serving in the Egyptian army during the early Middle Kingdom (c, 2050 B.C.E.-c. 1780 B.C.E). Presumably developed as a simplified version of Egyptian hieroglyphs, the alphabet enabled those soldiers—as well as ordinary people in general—to record their thoughts and to read those of more...

Child Labour is a serious problem in many parts of the world. Its presence in hazardous industries is a gross violation of human rights. If children are not dying in explosions, they are dying a slow but sure death in the glass, brass-ware, lock, slate, balloon, brick-kiln and other industries.  Not only are children working in hazardous industries, they are also engaged in the most hazardous processes in industries which adults do not want to touch. In the glass industry, children are primarily engaged in removing molten glass from the furnaces. Since the furnaces are designed for adults, the child's face is almost touching the wall of the furnace. It is not all. Accidents happen all the time and most of them go unreported. Child labour and its problems are intimately related to the extreme poverty. These children belong to the families of total have-nots who do not have any more...

A few miles south of Manhattan, New York, is a town called Travis. Up until 1930, that town was known as Linoleumville—the home of America's first linoleum factory, owned by British inventor Frederick Walton. Walton's love affair with linoleum began in the 1850s, when, as the story goes, he noticed a skin that had appeared around the top of an old paint can. This skin was the result of a simple reaction occurring between linseed oil in the paint and oxygen in the air. Most oil-based paints contain linseed oil; you've probably peeled off the rubbery solid that forms around the rim without even thinking about it. But Walton couldn't stop thinking about it. He embarked on a series of experiments that would eventually lead to a process for manufacturing floor tiles from linseed oil. His road to success was a rocky one. In 1860, he filed a patent for more...

Fireworks, familiar now in sound-and-light shows on dark evenings, to celebrate festivals and to entertain, were invented in China around 1,000 years ago, following the invention of gunpowder in the first century C.E. Bamboo tubes, filled with gunpowder, were thrown onto fires to create explosions at religious festivals, perhaps in the belief that the noise they made would scare off evil spirits. It is highly likely that some of these little bombs shot like rockets out of the fire, propelled by the gases they produced. The next step seems likely to have been to attach such charged bamboo tubes to sticks and fire them with bows. The earliest evidence of devices that could be described as firework rockets comes from a written report of the battle of Kai-Keng in 1232 during the war between China and Mongolia, in which the Chinese attacked with "arrows of flying fire." After Kai-Keng, the more...