Who invented the gas oven?

The domestic gas oven introduced by the English firm of Smith and Phillips is one of the first such ovens to be put on the market in an age of coal and wood stoves(1855). Cooking fuel is so costly that hot meals are prepared only two or three times a week in most British homes, but gas ovens will not come into common use for another 20 years. This answer comes directly from The Food Chronology by James Trager