Who holds the patent for the post-type fire hydrant commonly seen today?
Answer: unverified -- the patent record was lost in a fire
It's believed, according to Wikipedia, that the invention of the post-type fire hydrant is credited to a man named Frederick Graff, Sr., who was chief engineer of the Philadelphia Water Works around the year 1801. But the patent office in Washington, D.C. caught fire in 1836, destroying many patent records and leaving the identity of the inventor uncertain.