On Heating by Hot Water, 



power, and the boiler surface or absorbing power, are all calculated 

 with reference to a certain quantity of pipe, by urging the fire to 

 its utmost power, which is consistent with a proper duration of its 

 heat, the pipes to which it is ordinarily attached are heated to 

 their maximum, and the maximum heat is produced as required in 

 the building. If at this time an additional extent of duty is laid on 

 to the boiler, by opening the sluices which connect it with the pipes 

 of a greenhouse or pits, the temperature of the ordinary service 

 pipes is reduced, and the hothouse receives a diminished quantity 

 of heat just when it requires most. On the other hand if the com- 

 mon boiler be constructed of a size and power adequate to the 

 double service, when applied to the hothouse only, it will constantly 

 overheat it, and this effect can be prevented only by throwing open 

 the furnace door and allowing the fuel to burn to waste ; for be it 

 observed it is the area of the furnace bars which regulates the 

 consumption of fuel. It is true that by means of dampers and 

 skilful management some remedy may be found for these evils, but 

 nevertheless they will exist to a greater or less extent, and the 

 arrangement above mentioned should never willingly be adopted. 



The different temperature of stoves, to be heated from the same 

 boiler, may be regulated with the most philosophical accuracy, 

 by allotting to each house, quantities of pipe bearing a different 

 proportion to their respective surfaces of glass ; the difference thus 

 established will be maintained for all temperatures, unless accidental 

 circumstances of exposure to wind, or imperfect glazing, should 

 cause a variation, and the general heat of all may be regulated by 

 attention to one fire. 



Closely connected with the subject of heating is the providing an 

 adequate degree of moisture in the atmosphere heated ; indeed it is 

 upon this above every thing else that the perfection or imperfection 

 of an artificial climate consists, and it is by no means one of the least 

 advantages of hot water pipes, that they do not, like brick flues, dry 

 the atmosphere by absorbing its moisture. But this negative advan- 



