How a wire cage could stop a flame
The mesh worked by interrupting the chain reaction that keeps a flame moving. Burning gas heats the fresh gas just ahead of it until that gas ignites. In a fine wire gauze, the wires absorb and carry away much of that heat. The openings are small enough that the gas on the far side does not get hot enough to catch fire. Light passes through; the flame does not.
This principle is called flame arresting. The mesh does not smother the flame inside the cage. It contains the burning area, helping prevent a flame from traveling out and igniting a larger cloud of gas.
Why the danger belonged to the streets
London’s gas network ran through pipes beneath crowded streets and supplied lamps and buildings. A leak could let gas seep into a drain, cellar, or other enclosed space, where it might mix with air. If the mixture reached a flame, combustion could spread rapidly through the confined space. The threat was not simply that a lamp made darkness visible; it was that an ordinary ignition source could meet gas that had escaped beyond the lamp itself.
A mesh enclosure offered a practical safeguard at the point where flame and gas might meet. Its protection depended on the gauze staying intact and fine enough to cool the flame, so it was a barrier—not a guarantee against every leak or blast. Its lasting significance was an early lesson in urban safety: when a city distributes a flammable fuel through hidden infrastructure, the design must control not only where fuel flows, but also where a flame can travel.
