Rani Lakshmi Bai of Jhansi was a great patriot, she was born at Bitur on June'15,1834. She was named Manu Bai. In her childhood  she learnt the use of weapons. She had warlike qualities. She was a clever horse rider and a clever archer. She was married to Raja Ganga Dhar Rao of Jhansi. After her marriage she was named Rani Lakshmi Bai. She could not enjoy the pleasures of married life. She became widow after two years of her marriage. She had no issue. She wished to adopt a son. Lord Dalhausi, the Governor General of India, did not allow her to do so. He wanted to make Jhansi a part of British India. Lakshmi Bai stood against him. She opposed foreign rule. She refused to obey the orders of Governor-General. She adopted a son and declared herself independent. Nana Sahib, Tantia Tope and Kanwar Singh were waiting for more...

"... In the long run... the most daring prophecies seem laughably conservative." Arthur C. Clarke, novelist and writer In 1945, in an article entitled "Extra-Terrestrial Relays," British novelist Arthur C. Clarke described a way to bounce information off orbiting satellites so one side of the earth could communicate with the other almost instantly. Although the idea had been put forward previously by the Russian scientist Konstantin Tsiolkovsky, it was Clarke's detailed description that caught the attention of Harold Rosen of Hughes Aircraft Corporation. In 1961 the project, called the SyJichronou.s Communications Satellite program (or Syncom), was given funding to make it happen. A mere seventeen months later the satellite Syncom I was launched, but it stopped sending signals before it reached orbit. Syncom II, which followed in 1963, achieved a geosynchronous orbit (it traveled at an Inclined angle, so was not stationary above one spot) but nevertheless proved more...

A library is said to be the heart and soul of a college. The quality of education given in college can be roughly judged from the type of books in its library. Buildings alone do not make a college. Every college must have a good library. Our college library is housed in a big building. It has about thirty two thousand books on various subjects. Students come to the library and take books of their choice either for reading in the library itself or for study at home. Our college library is under the charge of a qualified librarian. She is an efficient and hard working lady. She is very helpful to students and members of the staff. She encourages that students to read as many books as possible. She is a strict disciplinarian. She makes sure that there is perfect discipline in the library. Our library is assisted by more...

"This is simply two single indin'ed planes in conjunction, expanding from hill to knoll..." Robert Fulton, engineer Use of the inclined plane for the transfer of boats between water levels dates back at least to the sixth. century B.C.E., when ships were transported across the Isthmus of Corinth in wheeled cradles. Early Chinese engineers also made use of the principle, employing double slipway constructions in their canals to haul vessels between levels. Modern inclined planes were pioneered by Italian architect Daviso de Arcort in Northern Ireland in the 1770s. Coal barges were raised or lowered in stages through a total of 190 feet (58 m) onto the Coalisland Canal, drawn on sloped rails by a combination of counterweighting and horsepower. The ambitious project was fraught with problems, and closed in 1787. In 1778 William Reynolds constructed England's first inclined plane in Shropshire, followed by a steam- driven version on the more...

Before the days of British engineer Henry Maudslay, (1771-1831), screws were handmade and depended on the skill of the craftsman. Consequently, no two screws were alike or interchangeable. In 1797 Maudslay created precision machinery that enabled identical screws to be produced. Without Maudslay's standardization, tasks such as building flatpack furniture would be extremely difficult. Maudslay was the skilled apprentice of the lockmaker Joseph Bramah, Their working partnership failed when Maudslay and Bramah fell out over pay, causing Maudslay to set up his own shop in another part of London. In a quest for precision, he devised a screw-cutting lathe capable of cutting down reliably to a ten-thousandth of an inch. To existing lathe designs Maudslay introduced gears and a lead screw that changed the pitch (distance between a complete turn) of the screw. This allowed him to cut a range of thread pitches from the same machine, rapidly and with more...

In 1967, IBM was looking for a better way of sending software to its customers. Their popular System/370 mainframe computers "booted up" from big, heavy magnetic tapes, which were slow and expensive to ship. Engineer David L Noble (b. 1918) tried all sorts of improvement schemes, from better tape systems to vinyl records, just like those used for music. None of them were right for the job, so Noble proposed a new system based on a flexible disk of magnetic material. Developed by IBM over the next few years and finally released commercially in 1971, IBM's 8-inch (20 cm) "floppy" disk was made from flexible plastic. After a hunt for a package for mailing the new disks, the engineers had the idea of making a protective envelope part of the design of the disk itself. The disk was sandwiched into a square jacket that included a fabric liner—a built-in cleaning more...

"Publishing [verse] is like dropping a rose petal down the Grand Canyon and waiting for the echo." Don Marquis, U.S. humorist, journalist, and author Sonar (which started as an acronym for sound navigation and ranging) is a technique widely used in shipping to detect nearby vessels and underwater obstructions. The word was coined by the Americans during World War II. The British also call Sonar, ASDIC, which has been daimed to stand for Anti-Submarine Detection Investigation Committee. There are two major kinds of sonar, active and passive. Active sonar produces a sound "ping"' and then measures how long it takes a reflected pulse to return to the ship. The sound source and receiver are continually rotated, so that the direction of the echoing body can be found. Lower frequencies are used if the reflector is a long way off. Passive sonars listen without transmitting. The first Sonar devices were passive more...

While studying for his degree, Herbert Henry Dow (1866-1930) became interested in developing more economical ways of extracting bromine from the underground brine reservoirs of Michigan in the United States. Dow, a man with a business acumen that matched his intellect, recognized that the use of bromine in medicine and the photographic industry meant there was a potential for massive profits. By 1889 he received his first patent for a new extraction process and immediately set up his own company, which went bankrupt within the year. Undeterred, Dow continued his investigations and by 1891 had patented the Dow Process. If a current is run through the brine, a process known as electrolysis, the negative bromide ions collect at the positive electrode, from where they can be collected. Dow knew that he had to compete in the European market, where prices were controlled by a cartel of German companies called the more...

"We've run these bulbs almost 10,000 hours in test cases, and there's no wear and tear." Michael Dry One of the goals of good lighting is to produce a radiation that has an energy distribution very similar to the sensitivity of the human eye. Michael Dry and Charles Wood decided that the ideal radiator would be ionized molecular sulfur (82), which produces a continuous spectrum as opposed to a line spectrum. About 73 percent of the light emission is in the visual spectrum, with only 1 percent in the ultraviolet. Sulfur plasma is extremely corrosive so normal tungsten electrodes could not be used. Dry and Wood decided to use a magnetron power source rather like those used in microwave ovens, the sulfur being contained in a golf ball-sized quartz bulb. However, the sulfur inside the bulb gets extremely hot and the bulb has to be continually rotated and cooled by more...

"When I talked to people about it, they said it couldn't be done..." Dr. Patricia Bath In nearly all circumstances, pointing a laser at your eye is a bad thing, but if you have cataracts it may just restore your sight. Cataracts are a leading cause of blindness. The disorder occurs when the part of the eye that focuses light—known, not surprisingly, as the lens—turns cloudy. This is a process that occurs in almost all of us if we live long enough. Unfortunately, currently there is no viable way to make a cloudy lens transparent again, and so ophthalmologists are forced to resort to other means to alleviate the problem. The current method of dealing with a cataract is to remove the lens of the eye. One problem is that taking out the lens in its entirety requires a rather large incision into the eye in order to remove it. more...