The Bessemer process was the first inexpensive industrial process for the mass-production of steel from molten pig iron prior to the open hearth furnace. The key principle is removal of impurities from the iron by oxidation with air being blown through the molten iron. The oxidation also raises the temperature of the iron mass and keeps it molten.
Related decarburizing with air processes had been used outside of Europe for hundreds of years, but not on an industrial scale.[1] One such process has existed since the 11th century in East Asia, where the scholar Shen Kuo describes its use in the Chinese iron and steel industry.[2][3] In the 17th century, accounts by European travelers detailed its possible use by the Japanese.[4]
The modern process is named after its inventor, the Englishman Henry Bessemer, who took out a patent on the process in 1856.[5] The process was claimed to be independently discovered in 1851 by the American inventor William Kelly,[4][6] though there is little to back up this claim.[7][8][9][10]
The process using a basic refractory lining is known as the "basic Bessemer process" or "Gilchrist-Thomas process" after the discoverer Sidney Gilchrist Thomas
For almost 30 centuries—from its unification around 3100 B.C. to its conquest by Alexander the Great in 332 B.C.—ancient Egypt was the preeminent civilization in the Mediterranean world. From the great pyramids of the Old Kingdom through the military conquests of the New Kingdom, Egypt’s majesty has long entranced archaeologists and historians and created a vibrant field of study all its own: Egyptology. The main sources of information about ancient Egypt are the many monuments, objects and artifacts that have been recovered from archaeological sites, covered with hieroglyphs that have only recently been deciphered. The picture that emerges is of a culture with few equals in the beauty of its art, the accomplishment of its architecture or the richness of its religious traditions.
Predynastic Period (c. 5000-3100 B.C.)
Few written records or artifacts have been found from the Predynastic Period, which encompassed at least 2,000 years of gradual development of the Egyptian civilization.
Neolithic (late Stone Age) communities in northeastern Africa exchanged hunting for agriculture and made early advances that paved the way for the later development of Egyptian arts and crafts, technology, politics and religion (including a great reverence for the dead and possibly a belief in life after death).
Around 3400 B.C., two separate kingdoms were established near the Fertile Crescent, an area home to some of the world’s oldest civilizations: the Red Land to the north, based in the Nile River Delta and extending along the Nile perhaps to Atfih; and the White Land in the south, stretching from Atfih to Gebel es-Silsila. A southern king, Scorpion, made the first attempts to conquer the northern kingdom around 3200 B.C. A century later, King Menes would subdue the north and unify the country, becoming the first king of the first dynasty.
In the Archaic Period, as in all other periods, most ancient Egyptians were farmers living in small villages, and agriculture (largely wheat and barley) formed the economic base of the Egyptian state. The annual flooding of the great Nile River provided the necessary irrigation and fertilization each year; farmers sowed the wheat after the flooding receded and harvested it before the season of high temperatures and drought returned.
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