OECHIDS. 



559 



8 to 10 feet. The brickwork of the house 

 should be carried up to the level of the stage, 

 and above that the sides should be of fixed 

 glass, not movable to act as ventilators, as air 

 admitted on a level with the plants is not good 

 for Orchids. Ventilation from below should be 

 provided by openings in the brickwork just 

 above the ground-line, so that the air enters 

 beneath the stages. These openings should be 

 about 18 inches in length and 6 or 9 inches 

 in height, and be placed about 9 feet apart 

 on both sides of the house. These should be 

 the principal means of ventilation, top venti- 

 lators being used only to allow of the egress of 

 bad air, for it should be remembered that even 

 the laps of the glass supply some top venti- 

 lation. The openings should be fitted with 

 sliding traps or covers, so that the admission 

 of air may be easily regulated. The top ven- 

 tilators should be at the highest point in the 

 roof, and may be made in whatever may be 

 thought the most simple and convenient way. 

 Usually small sashes are provided, which may 

 be opened to the desired extent either by cords 

 or by some mechanical arrangement. Beyond 

 these it is well to provide a small ventilator at 

 each end of the roof at the highest point. The 

 inside of the roof should have stout wires 

 stretched from end to end at intervals, to 

 provide accommodation for suspending the 

 plants grown in baskets and pans. Provision 

 should also be made over the sides of the walks 

 and other places where plants may be suspended, 

 to prevent the water from dripping from them 

 on to the plants beneath. Should the suspended 

 plants be numerous and directly over the stages 

 occupied by other plants, they should be taken 

 down to be watered, and allowed to drain before 

 being returned. Drip, whether it be from 

 plants overhead or from the roof of the house, 

 is very injurious to Orchids; and seeing this, 

 it is advisable in constructing the house to 

 prevent condensed moisture from dripping 

 from the rafters and sash-bars, by having them 

 grooved, or by fastening strips of zinc to the 

 under sides of the sash-bars for that purpose. 



Heating. — For a single structure intended as 

 an intermediate house, three rows of 4 -inch 

 piping extending round the house will be 

 ample. If three houses or divisions are pro- 

 vided, they should be arranged as East Indian 

 or warm house, Brazilian or intermediate house, 

 and cool or Odontoglossum house respectively. 

 The division next the boiler should be warmest; 

 and as it is in all cases best to have a good 

 command of heat, it should have four rows of 



4-inch piping on each side. The intermediate 

 division will require three rows, and the cool 

 one two rows. Stop-valves should be fixed in 

 the pipes to control the heat in each division. 

 Pipes to supply bottom -heat, or for heating 

 water-tanks, are not required. The hot-water 

 boiler should be so fixed that there is no pos- 

 sibility of sulphurous fumes passing from the 

 furnace or chimney into the house; it should 

 never be set in a stoke-hole under the house, 

 but outside and clear of it. 



Cool Orchid House (fig. 683). — Some amateurs 

 elect to grow cool-house Orchids only, and for 

 their model they may take the cool-house span- 



Fig. 683.— Cool Orchid House. 



roofed section of the range in three divisions 

 previously alluded to, with a width of 10 or 12 

 feet, and 8 or 9 feet in height, the path down 

 the middle of the house, and the staging on 

 either hand. Or it may be built as a lean-to or 

 three-quarter span facing north, north-east, or 

 north-west, cool Orchids succeeding best when 

 they escape the full effect of the solar rays 

 in summer. If convenient, the walk may be 

 sunk a couple of feet below the surface of the 

 ground, to assist in keeping the house cool in 

 summer. 



For glazing Orchid houses the best 21-oz. 

 English glass, in pieces 9 inches wide and 12 to 

 18 inches long, is best; but of course the glass 

 must be cut to fit the wood- work of the house; 

 if the panes are of moderate size, the cost of 

 replacing them, if broken by frost or otherwise, 

 is not great. For new houses it is best to have 

 the roof as light as possible, consistent with 

 stability. 



Stages and Floors. — If the span-roofed range 

 recommended is to be built to the widest 



