This is a photo of the facade of the gas meter house which formally stood at Kendal gas works. When the gas works was demolished in 1969, the facade was preserved and was subsequently erected elsewhere in the town.
Ex fumo dare lucem means from smoke to give light, which is an apt motto for a gas works. Apparently, the line originally comes from the poet Horace.
Kendal's gas meter house of 1825 is not the only piece of nineteenth century infrastructure which has a Latin motto. Perth's waterworks of 1832 carries the motto aquam igne et aqua haurio.
ex prep with ablative from
fumus, -i m smoke
lux, lucis f light