If a stream or jet of air is directed through a flame, fuel air mixing is enhanced and the jet exiting the flame is intensely hot. Jewelers and glassblowers engaged in lampwork have used the blowpipe since ancient times, with the blast being powered by the user's lungs. For small work, mouth-blown blowpipes may be used with candle flames or alcohol lamps. Starting in the late 18th Century, blowpipes have been powered by mechanisms, initially bladders and bellows, but now blowers, compressors and compressed gas cylinders are commonplace. While blowing air is effective, blowing oxygen produces higher temperatures, and it is also practical to invert the roles of the gasses and blow fuel through air. Contemporary blowtorches and oxy-fuel welding and cutting torches can be considered to be modern developments of the blowpipe.