"Few people are aware that practically all of the technical features of Franklin's... stove were copied from earlier inventors. [Louis] Savot's concept of a preheated draft was employed by Franklin... Prince Rupert's descending flue, invented in 1687, was also applied... The smoke rose in front of a hollow metal back, passing over the top and down the opposite side. ...Ducts similar to those invented by Nicholas Gauger, in 1716, were also incorporated in the Franklin stove."