MOUNTAIN BUILDING

M o U N t A i N     B u i L D i n G

The process involved n mountain building-termed orogenesis  occur as a result of the movement of the Earth's crustal plates. There are three main types of mountains: volcanic mountains, fold mountains and block mountains. most volcanic mountains have been formed along plate boundaries where plates have come together or  moved apart and lava and other debris have been ejected onto the Earth's surface. The lava and debris may have built up to form a dome around the vent of a volcano. Fold mountains are formed where plates push together and cause the rock to buckle upwards. Where oceanic crust meets meets less dense continental crust, the oceanic crust id forced under the continental crust. The continental crust is buckled by the impact. This is how folded mountain ranges, such as the Appalachian mountains in North America, were formed. Fold mountains are also formed where two areas of continental crust meet. The Himalayas, for example, began to form when India collided with Asia, buckling the sediments and parts of the oceanic crust between them. block mountains are formed when a block of land is up lifted between two faults as a result of compression or tension in the Earth's crust. Often, the movement along faults has taken place gradually over millions of years. How ever, two plates may cause an earthquake by suddenly sliding past each other along a fault line.

WHO INVENTED THE SAFETY PIN...............?

S a F E t y     P i N

The  safety pin was the invention of  WALTER HUNT.  HUNT  was a mechanic from New York, whose other inventions include a forerunner of the Winchester repeating rifle, a successful flax spinner, knife sharpener, streetcar bell, hard coal burning stove, artificial stone, road sweeping machinery, velocipedes, ice ploughs and mail making machinery.

In 1834, Walter Hunt built American's first sewing machine, which was also the first eye pointed needle sewing machine. He later lost interest in patenting his sewing machine, because he believed the invention would cause unemployment.

The safety pin was invented while Walter Hunt was twisting a piece of wire, trying to think of something that would help him pay off a fifteen dollar debt. On April 10, 1849, the safety pin was patented. Walter Hunt also thought little of his safety pin as an invention and soon sold the patent for four hundred dollars.

HOT AIR BALLOONS AND ITS PRINCIPLE

 H o T   A i R   B A L L o O n S

Hot air balloons are the oldest and most successful human carrying flight technology. The first balloons worked on the principle that when air is heated, it rises. A hot air balloon consists of a bag called the envelope that is capable of containing heated air. Suspended beneath is a basket which carries passengers and usually, a source of heat (mostly an open flame). Most balloons today use hot air made by burning propane gas. Soon after the first hot air flights, people realized that the gas hydrogen, which is almost fifteen times lighter than air, can be used instead . Filled with hot air or gas that is lighter than the surrounding atmosphere, a balloon travels by moving wind. Since the  wind direction changes with the altitude, the pilot navigates the balloon's direction by controlling the altitude, either by heating the air or by releasing ballasts. 

FLYING MACHINE

F L y I N g     M a C H i n E

On 17 December 1903 in an  American town called Kitty Hawk, two bicycle mechanics changed the World forever- they flew an airplane! On that historic day, the two mechanics, Orville and Wilbur Wright  made the World's first sustained, powered and controlled  flights in an airplane. The two were brothers who with their first flight marked the birth of modern aviation.

The term  'aviation' relates to the activities involved in the design , development, production, operation and use of aircraft. An aircraft is a vehicle capable of flying by being supported by air. It include fixed wing and rotary wing types (eg; helicopter), parachutes, as well as lighter than aircraft such as hot air balloons and air ships.

The 'Flyer" flown by the wright brothers on 17 December 1903 was 6.4 meters in length and flew at nearly 11 kilometers per hour (kph). In just over hundred years, mankind has bettered the record. For example, a Boeing 747, one of the World's most recognizable aircraft, in 100 feet longer than the Flyer's  first flight! Another  example is the Euro fighter typhoon. It is one of the World's most advanced new generation aircraft. It can travel at the speed of 2125 kph and takes just 2.5 minutes to reach a height of 35,000 feet. Similarly, aeroplanes have developed from rickety biplanes to the Airbus A380, the largest jetliner ever built. This giant plane has 22 wheels and its wingspan is as wide as the length of a football pitch!

An aircraft is an amazing invention through which mankind has overcome the pull of gravity that keeps most of the creatures tied to the ground. It has made possible for us to girdle the globe like birds, fly high and low, at great speed and even perform aerobatics and air shows with extraordinary precision and control. This is why an aircraft is not just a machine capable of flight, but also a source of joy and inspiration. 

GLIDER

G L i d E r

A glider is a light, small winged aircraft designed similar to a aeroplane, but with notable differences. The wings of a glider tend to be longer and slimmer than those of an aeroplane. The  cockpit is typically so small that it requires the pilot to be in a reclined position. Gliders are capable of unpowered flight. Some of these vessels have engines but others do not. The use of an engine is often to be prolong the flying time. A glider is generally used for recreational or sporting purposes, such as gliding or sky sailing. A para glider is  a free flying, foot launched aircraft. The pilot sits in a harness suspended below a fabric wing. heavier than air  unpowered aircrafts such as gliders, hang gliders and para gliders, may take off by launching forwards and downwards from a higher location.

MARS

M a R s

Mars known as the red planet, is the fourth planet from the sun and the outermost rocky planet. In the 19th century, astronomers first observed what ere thought to be signs of life in Mars. These signs included apparent canal like marking on the surface, and dark patches that ere thought to be vegetation. It is now known that the "canals" are an optical illusion, and the dark patches are areas where the red dust that covers most of the planet has been blown away. the fine dust particles are often whipped up by winds into dust storms that occasionally obscure almost all the surface. Residual dust in the atmosphere gives the Martian sky pinkish hue. The northern hemisphere of Mars has many large plains formed of solidified volcanic lava, where as the southern hemisphere has many craters and large impact basins. There are also several huge, extinct volcanoes, including Olympus Mons, which at 600 kilometers across and 25 kilometers high, is the largest known volcano in the solar system. The surface also has many canyons and branching channels. The canyons are were formed by movements of the surface crust, but the channels are thought to have been formed by flowing water that has now dried up. the Martian atmosphere is much thinner than Earth's with only a few clouds and morning mists. Mars has two tiny, irregularly shaped moons called Phobos and Deimos. Their size indicates that they may be asteroids that have been captured by the gravity of Mars.

THE EARLY 20th CENTURY

Architecture of the early 20th century is notable for radical new types of steel and glass  buildings particularly skyscrapers and the wide spread use of steel rein forced concrete. The steel framed skyscraper was pioneered in Chicago in the 1880s, but did not become wide spread until the first decades of the 20 th century. As construction techniques were refined, skyscrapers became higher and higher foe example, the Empire state building of 1929-1931 has 102 storeys. Many buildings of this period were constructed from light weight concrete slabs, which could be supported by cantilever beams or by pilotis (stilts), as in the villa Savoye . The early 20th century also produced a great variety of architectural styles. Despite their diversity, the styles of the period generally had one thing in common: they were completely new, with few links to past architectural styles. This originality is in marked contrast to 19th century architecture, much of which was revivalist.