By Mr. Joseph Hayward. 



43? 



EXPLANATION OF THE PLATE. 

 Fig. I. Ground Plan. 



A. The Boiler. 



B. B. B. B. The steam pipes which are continued through 



the larger pipes, C. C. C. C. C. C. 



C. C. C. C. C. C. The larger pipes, which being closed 



round the steam pipes at each end, form air 

 chambers. 



D. D. D. D. D. D. Small pipes inserted at one end of the air 

 chambers, and passing under the floor, com- 

 municate with the external air. 

 E. E. E. E. E. E. Small pipes for the admission of air into 

 the house, after it has been rarefied in the 

 chamber. 



Over the pipes, and so as to cover them, as marked by the 

 dotted lines, are placed boards to form a pathway. 



Fig. 2. Section. 



A. The boiler. 



B. The rising steam pipe. 



C. The declining return pipe, as inserted in the boiler. 



