As far as we know, Frederick Graff, Sr., Chief Engineer of the Philadelphia Water Works, was the inventor of the fire hydrant. We think he received a patent for his ground-breaking invention in 1801. We suspect he is the person to thank for protecting countless homes and communities from the ravages of an uncontrolled fire. The reason we don’t know for certain is because the evidence relating to the firefighting technology was destroyed — by fire.

Prior to the invention of the fire hydrant, fight-fighting techniques consisted of maintaining large cauldrons of water in strategic locations near population centers or filling underground tanks with water, both systems entirely dependent on whether sufficient water had been stored up to combat whatever nearby fire might break out. The fire hydrant was revolutionary in that it allowed for a continuous flow of water, guaranteeing that firefighters would not run out before the blaze was fully quenched.

If only this innovative firefighting system had been in operation near the U.S. Patent Office on December 15, 1836, we might not have to wonder about the true inventor of the fire hydrant. On that day, a fire broke out in the building where all U.S. patents were stored. An estimated 9,957 patents were destroyed in the blaze, wiping out official evidence of inventors’ contributions and rights to technological progress, including all records pertaining to the true inventor of the fire hydrant.

The government sought to restore its records. Many patent holders came forward with their copies of the official paperwork, and from those copies, the official records were recreated. Unfortunately, out of the 9,957 patents that were destroyed, only 2,845 were able to be restored. All patents on record from prior to the 1836 fire are officially classified as “X-Patents.”

Read more fun facts about patents.

Read about the time Abraham Lincoln helped put out a fire at the White House.