Urticaria is also known as 'nettlerash' or 'hives'. It consists of wheals-spots or patches of raised red or white skin-each of which usually clears away in a few hours, to be replaced by other fresh wheals. The wheals are usually itchy, painful or cause a burning sensation.
1 1893: the original Ferris Wheel was 80.4 metres (264 ft) tall. 2  Built for the World's Columbian Exposition in Chicago, Illinois, it was moved to St. Louis, Missouri, in 1904 for the Louisiana Purchase Exposition, and demolished there in 1906.
A Salute to the Wheel. Always cited as the hallmark of manâs innovation, here is the real story behind the wheel â from its origins to its reinvention. Evidence indicates the wheel was created to serve as potter's wheels around 3500 B.C. in Mesopotamiaâ300 years before they were used for chariots. (Jim Vecchi / Corbis)