HEATING ORCHID HOUSES. 37 



into the house, he replied, " There is no fear of that, for I 

 have got the boiler well covered over." Only a few months 

 afterwards I went to see the same collection, and found my 

 fears were realised ; the smoke had got into the house, and 

 had spoilt many of the plants. This is merely mentioned to 

 show the ill efiects of a boiler being set so that smoke can get 

 into the house. When outside , there is no fear of such a disaster. 

 Hot water boilers are now made of shapes and patterns 

 without end, and as most cultivators have some predilection in 

 this matter, I leave them to make their own selection. There 

 are, however, many things to be thought of before deciding this 

 question. If the locality is such as to render it impracticable to 

 dig far down into the ground before reaching water, or to 

 prevent a drain being put below the boiler, then the upright 

 form of boiler is neither suitable nor safe ; for in cases of flood, 

 during winter, the water may rise and put out the fire, unless 

 the stoke-hole is made water-tight, which may be a trouble- 

 some and expensive process. I would, however, by no means 

 depreciate these boilers. Then we have cannon boilers, tubular 

 boilers, common saddle boilers, terminal saddle boilers, tubular 

 arched saddle boilers, double L saddle boilers, improved tubular 

 boilers, convulate boilers, the duplex compensating boiler, and 

 boilers that require no setting, the makers of all being able to 

 give what are to them satisfactory reasons why the particular 

 form they adopt is the best. That we have this diversity 

 amongst boilers is no doubt a great advantage, for one that 

 may work admirably in one place, may not, through some 

 peculiarity of place or position, be so thoroughly satisfactory 

 in another. Moreover, the fuel most readily available in one 

 place, and which may suit one class of boiler, may not be so 

 readily obtained in another place, and therefore those who are 

 so situated will natm-ally have recourse to a boiler which will 

 consume the fuel which they can obtain for heating it. 



