Archives February 2013

"...a lanthorn, with pictures on glass, to make strange things appear on a wall, very pretty." Samuel Pepys, diarist The "magic" lantern was used to project still images onto a wall or sheet and was an early version of the slide projector. The idea has been understood for many centuries. Light, shining through a translucent picture, will project the image onto a light-colored flat surface. The earliest reference to the use of a lantern to project images is in Liber Instrumentorum by Giovanni de Fontana, written around 1420. Optics developed rapidly in Europe during the seventeenth century. As early as 1659, Dutch scientist Christiaan Huygens (1629-1695) had made a lantern with a lens to focus the light and produce a sharp image. Danish mathematician Thomas Walgensten (1627-1681) traveled throughout Europe in the 1660s, selling the lanterna magica. Numerous designs survive from this period and, in 1663, optician John Reeves of more...

"And they said to one another,  'Come, let us make bricks, and burn them thoroughly.'" Genesis 11:3 In ancient times, brick houses were made first, by compacting together wet mud and clay into slabs and leaving them to dry in the sun. Once solid, the bricks were piled up to fashion a basic building. However, the major problem with sun-dried bricks is that rainy weather can revert them to wet mud. It took brick makers a long time to arrive at a solution—buildings were constructed from dried mud blocks for more than 5,000 years before the fired brick appeared. Using a combination of clay, sand, and water, brick makers in the Middle East formed a pliable mass of matter called a clot. The clot was shaped in a wooden mold to create what is known as a "green" (that is, unfired) brick. This was placed in a kiln and baked more...

The Hindus enjoy many festivals. The diwali festival is one of the most important festivals. It is called to be the festival of Vaishyas chiefly. Diwali comes in the month of Kartik on Amavasya day after the rainy season. The farmers are happy as the crop of rice is ready. All the people remain busy for days in cleaning and white washing their houses and business premises. There is hardly a house of any Hindu which is not cleaned or white-washed on this day. The kachha walls and courtyards in villages are besmeared with dung and earth. It is said that Raja Ram Chandra returned to Ayodhya after fourteen years. He got victory over Ravana the king of Lanka. So the people of Ayodhya illuminated the city to welcome him and show their joy. Thus the festival is observed in the memory of Ram. There is hygienic point also. The more...

"I hit upon the idea of a chocolate bar dispenser, but replacing chocolate with cash." John Shepherd-Barron There was a time not so long ago when there was no such thing as a cash machine. If you wanted to withdraw some money, you had to go into a building and speak to a teller. Now, of course, it is possible to get cash from one of .over 1.6 million automated telling machines (ATM) worldwide, in stores, cinemas, and even the southern rim of the Grand Canyon. Exactly who we have to thank for this stroke of technological banking genius is a matter of some controversy. Luther George Simjian, a prolific inventor of his time, devised the very first "cash-point" in 1939. Installed by the City Bank of New York this cash machine saw little use except with "... prostitutes and gamblers who didn't want to deal with tellers face to more...

"Give me a lever long enough and a fulcrum on which to place if and I shall move the world" Archimedes, mathematician and physician The lever was first described in 260 B.C.E. by Archimedes (c. 287-212 B.C.E.), but probably came into play in prehistoric times. A lever can be used to raise a weight or overcome resistance. It consists of a bar, pivoted at a fixed point known as the fulcrum. Extra power can be gained for the same effort if the position of the fulcrum is changed. Levers may be divided into classes. First-class levers have the fulcrum in between the applied force and load, which are at opposite ends, such as with the seesaw. Second-class levers have the fulcrum at one end, and the applied force at the other, such as with a bottle opener. Finally, third-class levers have the effort in between the fulcrum and the load; more...

"Any of us who [have walked] away from an automobile accident is likely to have a dummy to thank." JackJensen, General Motors In the fate 1940s, the U.S. Air Force wanted data on how deployment of their newly designed ejection seats would affect the pilots who were strapped into them. For the first time, a crash test dummy was created to obtain the information. This very smart dummy was named "Sierra Sam" and was built in 1949 by American Samuel'- Alderson (1914-2005) in partnership with the Sierra-engineering Co. Prior to the arrival of the crash test dummy, human cadavers were used to guide safety design. Working with corpses was of course highly unpleasant, but also the human bodies were very limited in terms of the information they could convey to researchers. It was also impossible to use them repeatedly to any useful purpose, and although they gave limited information on more...

A war is never a good thing it takes away hundreds of lives. Leaving behind  thousands of widows and orphans. The financial burden due to war affects the economy of the country and development of country lacks behind. Since independence Kashmir has always been a bone of contention between India and Pakistan. Pakistan has desired to grab Kashmir, an integral part of India. She fought many wars against India but always lost them due to excellent bravery of our soldiers. On the other hand India has always tried to reconcile and wanted normalcy in the island. The Indian Government has declared time and again for maintaining friendly relations and peace with the neighboring countries. It has no intention of interfering in the internal affairs of any other country. But after Pakistan lost every war they started terrorism by sending intruders in India specially in Punjab and Kashmir to achieve their more...

The simple pulley enables the user to lift a load more easily by changing the direction from which the force is applied. When the rope is fixed at one end and another pulley is added, the system provides a mechanical advantage by multiplying the applied force, making it possible to lift heavy loads. More pulleys can be added to the system, now known as a "compound pulley" system, further multiplying the effectiveness of the force applied. As an indication of the benefit of the system, the addition of a second pulley to a one-pulley lifting mechanism halves the amount of force required to make the lift. A third pulley, properly rigged, reduces the amount of force required to a quarter. In 250 B.C.E., the Greek scientist and.-, .inventor Archimedes (c. 287-212 B.C.E.) adopted this principle by mounting several pulleys on the same axle to create a "block" that was much more...

"Slebe's design... remained In use essentially unchanged by the Royal Navy until]989." English Heritage The standard diving suit, or "hard-hat" diving suit, was a major advance in diving technology. Early diving suits were crude and inflexible and imposed major restrictions on divers' movements, such as an inability to invert. A brilliant German inventor by the name of Augustus Siebe (1788-1872) changed all that with his innovative "closed" helmet suit—a design that remained essentially unchanged until fiberglass SCUBA suits arrived in the 1960s. After learning metal craft and working as a watchmaker, and following service as an artillery officer in the Prussian army at the Battle of Waterloo, Siebe moved to England in 1815. While living in London he stumbled across the solution to creating a more practical diving suit. Previous designs—so- called "open dress" suits—were simple diving bells that trapped air for breathing, but these took in water when the more...

In the early 1940s plastics were still relatively new compounds and their practical applications had not yet been fully realized. Early plastics were brittle, greasy, and had a rather unpleasant odor. It would take an ex-tree surgeon by the name of Earl Tupper (1907-1983) to come up with the perfect plastic. Tupper worked at the chemical company DuPont, where he learned about the design and manufacture of plastics. In 1938 he founded the Earl S. Tupper Company, which manufactured parts for gas masks during World War II. After the war, he turned his attention toward creating a peacetime product. Tupper discovered a way of turning polyethylene slag—a by-product of crude oil refinement—into a strong, resilient, grease-free plastic that he called Tupperware®. By 1946 Tupperware® was on the market in an array of brightly colored incarnations: cigarette cases, water tumblers, and food storage containers. In 1947 he patented the Tupperware® seal, more...