HOT WATER AND STEAM. 175 



raised a sufficient height above the pipes, to 

 keep them constantly supplied ; which, by the 

 heat of the fire, causing the water to keep on 

 the move, will gradually force through all the 

 pipes, and cause the last pipe, or further end of 

 the return, which is also fixed into the boiler, 

 as a funnel to convey the water back into the 

 boiler. 



This simple (and I may add elegant) mode 

 of heating with hot water, when compared to 

 to flues, is so easy to manage, the trouble so 

 light, and the expense attending it being in- 

 finitely less than any other method, will, no 

 doubt, eventually supersede every other mode 

 of heating. 



When the hothouse is very long, with divisions*, 

 (the same as directed for heating by flues,) it may 

 be requisite to have more fire-places and boilers, 

 which may be done at convenient distances at 

 the back. 



When the boiler is once filled, and like- 

 wise, all the pipes thereto attached, (they, 

 being below the top of the boiler,) the principal 

 trouble will be to attend to the fire, and occa- 

 sionally fill up the boiler. Should the tempe- 



