468 



PITS AND FRAMES. 



shelves may be made wider, and used for 

 mushrooms. Stones are placed on each 

 side of the passage, at c c, for the standards 



Fig. 661. 



i i 



to be placed on that support the bearers 

 of the shelves, and which are mortised at 

 d d. The stones should be about 6 inches 

 square on the surface, and 3 inches thick, 

 and the standards about 3| inches square." 

 The standards and cross-bearers are fitted 

 up in the usual manner, as will be seen by 

 a glance at the diagram. "When the 

 standards and cross-bearers are fixed, the 

 shelves may be formed by laying along 

 the latter boards 1^-inch thick; and it 

 will be convenient, when removing or 

 putting fresh dung in, if a board 8 inches 

 broad and 1 inch thick is placed behind 

 the standard at i, or cut so as to come 

 flush with it. When the shelves are fixed, 

 a trench 9 inches deep is made in the 

 passage 1 1, for the reception of the hot- 

 water pipes ; on each side this trench a 

 brick wall, n n, is built, to prevent rub- 

 bish from falling in. The bottom of the 

 trench must be puddled with clay, so that 

 the water thrown on the pipes may not 

 escape. The pipes used are inch-and-half 

 bore, and they are laid in the trench 3 

 inches apart. A wooden trellis, o, is 

 placed over them, resting on the brick 

 walls n n, and forming a path. Fig 662 

 shows the section of the furnace for heat- 

 ing the pinery" — as the same fuel used 

 for the latter heats the mushroom-house 

 also — " and it is so constructed that the 

 same quantity of fuel is found sufficient 

 to keep up the temperature in both 

 houses. When a strong fire is required 



another 



in the furnace b, which heats the flues 

 in the pine-stove, it is sufficient for the 

 j,. 662 boiler a, which is 



1 1 k ' placed on one side 



of it. When the 

 weather is mild, 

 the fire in the fur- 

 nace c is sufficient 

 for both purposes ; 

 but when cold 

 weather sets in, 

 then made under the 

 boiler at c, which is sufficient to keep 

 the water in the pipes in circulation. 

 The heat from the furnace c passes over 

 the left side of the boiler, and enters the 

 flue heated by the furnace, as shown by 

 the arrows in the sketch. A flange is 

 placed on the flow-pipe, by which it is 

 fixed over the top hole in the boiler a. 

 This pipe runs horizontally, and is at- 

 tached by an elbow to the pipes laid in 

 the trench of the mushroom-house. The 

 return-pipe is fixed in the boiler below 

 the flow-pipe, and on it is screwed a tap 

 to let out foul air when required. When 

 the mushrooms want steaming, take a 

 fine rose watering-pot, and sprinkle the 

 pipes with it till the steam arises so 

 thick that objects cannot be seen at the 

 farther end of the house. Steaming is 

 better than watering over -head for 

 mushrooms, as much water destroys the 

 spawn." 



The system of heating and steaming 

 recommended here is excellent. We 

 think, however, that 3-inch pipes would 

 in the end have been found better, as 

 those of so small a calibre will soon be 

 choked by the formation of rust and 

 mineral deposits. The whole framework 

 we would here, as we recommended for 

 Oldacre's mushroom-house, have of iron ; 

 the shelving of slate or thin pavement ; 

 and were the shelves perforated thickly 

 with holes, perhaps it would be an advan- 

 tage — at least it would tend to guard 

 against damp at the bottoms of the beds. 

 The shelves b b b, which are only 1 foot 3 

 inches broad, are rather too narrow for 

 holding rhubarb roots ; perhaps it would 

 be better to force the rhubarb on the 

 ground floor. The idea of puddling 

 under the pipes is also good, as a slight 

 vapour will arise from it, and so keep the 

 atmosphere of the house moderately 

 humid. 



