136 HOT-HOUSE. 



full play all round the boiler, carrying the flue about forty 

 or fifty feet through the house, that no heat may be lost; 

 attach two pipes to the surface or top of the boiler, if it is to 

 heat right and left, but only one pipe if the heat is to be 

 carried in one direction ; distribute the pipe wherever re- 

 quired, giving it an ascent of not lfcss than six inches to the 

 titty feet, more if it can be done return the pipe, entering 

 t into the lowest part of the boiler; the greater the ascent 

 and descent, the more rapid the circulation. The joints of 

 the pipe are closed by soft hemp rope, firmly rammed up and 

 closed by a mixture of white and red lead made to the con- 

 sistency of putty. These joints are preferable to those of lead, 

 which expand and contract by strong heat, requiring to be 

 hammered up frequently during the season they can also 

 be very readily taken apart, when removal or alteration is re- 

 quired. It must be observed that air tubes have to be inserted 

 into the highest part of the pipes at each extremity, and also 

 one over, or near the boiler, for the conveniency of supplying 

 water. If the pipes diverge from the boiler to two extremes, 

 each extremity must be on a level, which otherwise will cause 

 an unequal diffusion of heat. 



Example. If a house to the right of the boiler one hun- 

 dred feet long has the extreme end of the pipe elevated one foot 

 above the level of the boiler, a house fifty feet long to the left 

 must have the same elevation, otherwise the heat will be the 

 greatest where the pipe is highest. 



This we consider the most economical method of heating by 

 hot water, and it is by far the most simple simple indeed 

 in every part, though volumes have been written on the sub 

 ject. 



Bark Pit. We consider such an erection in the centre of 

 a hot-house a nuisance, and prefer a stage, which may be con- 

 structed according to taste. It should be made of the best 

 Carolina pine, leaving a passage all round, to cause a free 

 circulation of air. The back and end paths may be about two 

 feet wide, and the front three feet. The angle of the stage 

 should be parallel with the glass, having the steps from six 

 inches to one foot apart. 



Where there are some large plants, they may stand on 

 the floor behind the stage, or on tressels, according to their 

 height 



