Leigh’s new picture of London; or, A view of the … British metropolis, 1818
Gas lights in London during the Regency were a thing of wonder rather than commonplace. 1807 saw experimental lamps installed in Pall Mall to celebrate George III’s birthday and by 1813 the Gas Light and Coke Company lit up the Westminster Bridge (https://web.archive.org/web/20151225124433/http://www.theguardian.com/culture/2015/dec/25/londons-last-gas-street-lamps). By 1826 almost every large city and town in Britain had gas street lighting (http://www.nationalgasmuseum.org.uk/gas-lighting/). They continued to increase in popularity, where by the 1860s a thousand gas works cropped up to meet the fuel demands. Gas lighting in the home was not prevalent until the 1840s, when it began to appear in wealthier, urban homes (http://www.lucyworsley.com/a-quick-history-of-domestic-lighting/).
Like many inventions and technologies of the time, it seemed to be a race between the British and French for “firsts”. Paris would gas street lights in 1820.
Light Without a Wick: A Century of Gas-lighting, 1792-1892 : a Sketch of…,1892,
The perceived benefits of gaslight:
Some information concerning gas lights, 1816
