THE TANK MODE OF HEATING. 



199 



one time, yet each bed may be regulated 

 to a different degree of heat, thus form- 

 ing four distinct beds to be heated as 

 circumstances may require. These aper- 

 tures are formed with short pieces of 



4-inch iron pipe, cemented into the brick- 

 work, and the circulation is regulated by 

 having plugs to fit the pipes. This plan, 

 though so simple, we believe to be new ; 

 and the advantages arising from it must 



Fig. 256. 



Fig. 257. 



be apparent to every one. Steam, if re- 

 quired, may at any time be obtained by 

 opening the doors at which access is pro- 

 cured to the apertures for increasing or 

 diminishing the circulation of the water." 

 The following will explain the figure : " a 

 represents the boiler, &c. ; I flow and 

 return pipes ; c stoke-hole ; d plug-holes 

 for stopping the circulation of hot water, 

 if bottom heat is required only for one 

 house, or for part of one house ; e, doors 

 for getting access to the plug-holes, and 

 also available for steaming the house ; h, 

 potting benches." The house is 51 feet 

 9 inches long, 11 A feet wide, and 6 feet 

 9 inches high under the ridge. 



Corbet fs system of open pipe or tank 

 heating. — This method, for which Mr 

 Corbett took out a patent in 1839, seems 

 little, if at all different, from that de- 

 scribed by Dr Neill in the article " Hor- 

 ticulture," in the " Encyclopaedia Brit- 

 annica," as practised as early as 1 832 by 

 Mr Smith, in the gardens of the Earl of 

 Hopetoun, and also exemplified much 

 about the same time by Mr Jones of Bir- 

 mingham, in the nursery of Mr Knight, 

 at Chelsea. As a mode of heating, it has 

 its advantages. The troughs used by 

 Mr Corbett in the nurseries of Messrs 

 Lucombe and Pince, at Exeter, and which 

 Mr Pince pointed out to us last year, and 



