Steel

            Have you ever wondered how skyscrapers came about? Before there were skyscrapers, there were towers. Made of heavy stone, towers had thick, sturdy walls, but the rooms were dark and cramped. The reason the towers were so dark was because having too many windows would weaken the structure. Soon Gothic cathedrals joined the quest for height. Long, stone arms, called flying buttresses, supported the cathedral's heavy weight, allowing the walls to be filled with colorful glass windows.
             George A. Fuller was the first person to invent the sky scrapper. Fuller worked on solving the problems of "load bearing capacities" of tall buildings. Fuller built the Tacoma building in 1889, the first structure ever built where the outside walls did not carry the weight of the building. In order for Fuller's idea to work he needed a material and enough of that material to make a steel cage that could support the weight. The Flatiron Building was one of New York City's first skyscrapers, built in 1902 by Fuller's building company.
             With an idea as valuable as Fuller's someone had to step up to the plate and create a way to mass-produce steel inexpensively. That man was Henry Bessemer of England. In 1855, Bessemer developed the idea of "air blowing the carbon out of the pig iron", which is still used today to make modern steel.