Description of a mode of heating Pits and Stoves. 441 



top of the fire place which heats this flue, a boiler is fixed, 

 which is supplied with water by a ball cock ; the lid or cover 

 to the boiler has a pipe from its top, which is carried into 

 the chamber above the flue, and the steam which is pro- 

 duced by the water when boiling is thus conveyed into, and 

 fills the entire chamber. From holes which are made in the 

 sides of the pit, at about four feet, or the width of each light, 

 apart from each other, both in the back and front of the 

 chamber, the steam and heat from the chamber are admitted 

 into the house at pleasure, and when this is not desired, the 

 steam escapes by another opening out of the chamber into 

 the external air. The holes for the admission of the steam 

 and heat into the house are two inches and a half wide, and 

 commence in the chambers as high as the arch will allow, as 

 the steam and heat ascend thereby more easily ; the openings 

 are three inches below the top of the curb in the sides of 

 the pit, and are stopped by wooden plugs when not in use. 

 The escape-pipe or opening from the chamber is near four 

 inches wide, and is stopped by a valve when the steam is in 

 use. In the pit, which is thirty feet long, by thirteen feet 

 wide, the flue after passing through the middle of the 

 chamber is carried along the front, and then by one end to 

 the chimney which is near the furnace. 



It is obvious that the same fire which heats the flues 

 causes the water to boil in the boiler over it. A pit of the 

 above dimensions requires a boiler of about thirty eight gal- 

 lons. The boiler should be made very strong at the bottom ;. 

 and the lid or cover should be screwed on so close that no 

 steam can escape, except through the pipe, which must be 

 six inches in diameter. As the steam passes freely through 



