London's Crystal Palace, housing the first world's fair, opened to the public on May 1, 1851. It used a revolutionary modular design of mostly cast iron and plate glass, had nearly one million square feet of floor space, and was over a third of a mile long. Yet it was constructed on time and budget in only five months, financed entirely by public donations.  We will see how the Palace was used for the next 85 years before it suffered its ultimate fate.