The revolution in materials came first, with the use of cast iron, drywall plate glass, and reinforced concrete, to build structures that were stronger, lighter, and taller. The cast plate glass process was invented in 1848, allowing the manufacture of very large windows. The Crystal Palace by Joseph Paxton at the Great Exhibition of 1851 was an early example of iron and plate glass construction, followed in 1864 by the first glass and metal curtain wall. These developments together led to the first steel-framed skyscraper, the ten-story Home Insurance Building in Chicago, built in 1884 by William Le Baron Jenney. The iron frame construction of the Eiffel Tower, then the tallest structure in the world, captured the imagination of millions of visitors to the 1889 Paris Universal Exposition.