Archives August 2013

"...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...

Rail travel is one of the safest ways to get around in the modern age. The pioneer responsible for much of this safety record was the visionary inventor and industrialist George Westinghouse (1846-1914). Before he invented his revolutionary air brake, slowing and stopping a train was an exercise fraught with risk. Each separate car of the train needed its own brakeman to manually operate brakes on its own set of wheels. Accidents caused by uncoordinated braking were frequent and Westinghouse realized that the poor safety of trains was holding up the whole industrialization of the United States. He spent several years working on a replacement for brakemen's manual labor. Various models failed until, in 1868, he found a solution. He placed an air compressor inside the train driver's cabin and connected long air hoses to it. These hoses traveled the length of the train and were attached to brakes on more...

We all know that kindness is a great virtue and an important duty of man. But most men take it in a limited sense and think that it is enough if they are kind to their fellow men only. Other creatures, birds and beasts too feel pain and we should be kind to them. All living creatures—men, birds and beasts are the creation of God. So He is their common father. It must, therefore, be His desire that the virtue of kindness should be extended to all these creatures alike. No doubt that man has become the lord of the world by virtue of his intellect. But that is the stronger reason why he should be kind to his weaker fellow creatures. We often forget our duty and treat animals cruelly, even those that do us good. Let us take the case of the cow. It gives us milk, the more...

The cluster bomb has courted controversy since its induction in modern warfare in 1939. A conventional bomb consists of a single container carrying an explosive charge that is designed to explode upon impact. The cluster bomb differs through the addition of an outer casing carrying dozens of small bomblets. The casing splits open in mid-air, releasing a shower of smaller bomblets that impact over a broad area. Often dropped by parachute, cluster bombs are highly versatile, if not particularly accurate. They can wreak havoc on soft or unarmored targets such as airfields and formations of men; cluster bombs containing shrapnel are able to pierce armored tanks and penetrate concrete. Cluster bombs really came to the fore during the Vietnam War. U.S. forces carpet- bombed the dense forests of Vietnam, Laos, and Cambodia with cluster bombs carrying chemical weapons such as napalm. The bombs were designed to set fire to the more...