Fire extinguisher

Ambrose Godfrey patented the first fire extinguisher in 1723: a barrel of fire-suppressant liquid with a chamber of gunpowder that, when ignited, would explode and scatter the liquid over a blaze. The concept—delivering fire-fighting material rapidly and forcefully—established principles that all later extinguishers would refine.

The device was crude but represented systematic thinking about fire suppression. Previous fire fighting relied on buckets, pumps, and demolition to create firebreaks. Godfrey's extinguisher offered a self-contained response: position it near the fire, trigger the explosion, and the suppressant would distribute automatically.

Development continued through the 19th century. The soda-acid extinguisher (1866) used a chemical reaction between sodium bicarbonate and sulfuric acid to pressurize and expel water. Carbon dioxide extinguishers (1924) deployed gas that smothered flames without water damage. Dry chemical and foam extinguishers addressed specific fire classes: electrical fires, grease fires, metal fires.

The key insight was that different fires need different treatments. Water on a grease fire spreads burning oil; water on an electrical fire risks electrocution. Modern fire classification systems (Class A for ordinary combustibles, Class B for liquids, Class C for electrical, and so on) guide extinguisher selection. A kitchen fire requires different chemistry than a server room fire.

Fire codes now mandate extinguisher placement in commercial buildings, creating the ubiquitous red cylinders mounted on walls. Training programs teach the PASS technique: Pull, Aim, Squeeze, Sweep. What Godfrey invented as a specialized device became standard safety equipment.

The technology seems simple in retrospect—pressurized containers that spray suppressants—but required understanding fire chemistry, materials science, and mechanical engineering to develop into reliable devices that untrained users could operate in emergencies.