AND CONSERVATOUY. 



25 



wire gauze, and the gas passes up through the pumice stone, and 

 is there lighted. There are two distinct sources of heat, one 

 by the flow-pipe (c), whicli passes round the house and returns 

 to the boiler at D, and the other by means of the hot-air pijie 

 (g), which is carried along under a shelf against the back wall, 

 and then out of the house at the other end. The only pre- 

 caution necessary is to prevent an accumulation of air in the 

 boiler or pipes, and every time the gas is lighted, the stop- 

 cock at c should be opened to allow of its escape. The heat 

 should at first be very slight, and may be increased as the 

 circulation is established. 



rc~ 



A— Copper Gas Boilfr. 



B— Wrought-iron Jacket or 

 Cover, to prevent tlie too 

 rapid escape of lieated ;i r 

 and tlie fumes of the sras 

 entering tlie greenhouse. 



C— Ring G.is Burner. 



D-Supply-cistern. This can 

 be placed as shown, or in 

 any convenient position. 



E— Supply-pipe from Cistern 

 to Boiler. 



E— Flow-pipe, for heated water 

 from Boilei-. 



G— Return Pipe. 



H-Hot-air Escape Pipe 



GAS-HEATTXa APPARATrS OF THAMES BANK IROX C03irA>"r. 



(Bi)iler 10 inches high, 9 inches diameter.) 



Probably the best gas-heating apparatus now before the 

 public i.s that manufactured by the Thames Bank Iron Com- 

 pany. The apparatus consists of a boiler (a), capable of heat- 



