42 THE amateur's GREE>'HoUSE 



EXAMPLE OF HEATINO OK THE LEVEL. 



pipe cliiefly. We preferred to heat the houses in the orthodox 

 fashion, and selected for the purpose one of the upright conical 

 boilers of the Thames Bank Company, and left Mr. Dunbar to 

 fight it out, and the result of his operations was that the lower 

 house was heated with four-inch flow-and-return placed side by 

 side in the front of the house, on a dead level, and from these 

 heat enough was derived to keep all safe in severe frosty 

 weather. 



The figure will show that the Paxtonian stands slightly 

 above the level of the lean-to ; so wehad but to make sure of a fire 

 in the furnace, and the heating of this bouse was an easy matter. 

 The pipes had, however, to be taken a distance of twenty-five 

 feet from the furnace to the Paxtonian ; and, as this would 

 cause a great waste of heat, a long, trough-like wooden box 

 was fitted to the dwarf wall on which the pipes rested, and 

 they were thus enclosed from the weather. The box was 

 covered with stout shutters clothed with felt, and it became 

 immediately a dark forcing. pit, and has been used ever since, 

 during the winter and early spring, for forcing sea-kale, aspa- 

 ragus, rhubarb, <fec. The pipes in this box are of two inches 

 bore, to cause a quick flow, and make the waste of heat the 

 least possible ; but, as soon as they enter the house, they are 

 enlarged to four inches, and thus they pass all round the house, 



