Abstract: A cowper having no combustion shaft is presented wherein a combustion chamber is topped by a cupola and is positioned above the chequerwork. One or more burners are arranged symmetrically on the cupola wall, each burner being installed at a specific angle relative to the horizontal plane through the cupola. A burner duct is installed in the cupola masonry in front of each burner, the outlet of the duct widening conically at the entry into the cupola and being aligned at a particular angle towards the cupola arch.