The first gas lighting appeared on Pall Mall in 1807 and began to spread from 1812 when the London and Westminster Gas Light and Coke Company was created. Early gas was created by heating coal which then released mainly hydrogen. More about present day London’s Gas Lamps and where to see them. The best place being the broad avenue of Kensington Palace Gardens. The gardens do close at dusk but there is information about turnstile exits here.
A more intense light could be created by directing an oxyhydrogen flame upon a cylinder of quicklime (calcium oxide). The resulting light was commonly known as limelight and used for stage lighting. Hence the term “being in the limelight” is used to mean being the center of attention.
These gas lamps are just outside the British Museum with a Penny Farthing bicycle further down the page.