By Mr. John Haythorn. 



511 



c Flue. 



d Cavity round the flue, the top being formed of stone. 

 e Internal cavity. 



f Pipe for supply of water to the top of the flue. 

 Fig. 8. Front of the flues, cavities, and borders. 

 a The flue. 

 b The cavity. 



c Holes through which water is poured into the cavity. 

 d The border. 



e Plug to stop the holes in the cavity. 



