A fire destroyed the patent for fire hydrants

In the ultimate example of irony, the patent for fire hydrants was itself destroyed in a fire. In 1836, a large fire destroyed the patent office in Washington, DC, destroying all US patent records up until that point. Frederick Graff, the creator of the fire hydrant, supposedly filed his patent at that office, which means that his fire hydrant patent was destroyed in the fire. Working as the chief engineer of Philadelphia Water Works, he first patented the hydrant around the year 1801.