85 



and I have seen the late Mr. Percival's fine Cattleyas being absolutely 

 blown about by brisk sea breezes, and Dr. Paterson in warm Bridge 

 of Allan has adopted a similar S)stem with equal advantage. For 

 cool Orchids a liberal supply of air during the greater portion of the 

 year is essential, and in one of the largest trade establishments small 

 wooden pegs are placed between the laps of the glass, so that there 

 is a space of an eighth of an inch between each two panes, and a similar 

 space at the bottom of the rafter. In the same place ihe walls are 

 constructed so that there is a moveable half-brick at the end of each 

 whole brick just below the bide shelf and opposite a hot- water pipe. 

 These act as plugs, which are removed in spring immediately the 

 frost has depaned and are not put in again until autumn, thus afford- 

 ing a free admission of air both day and night. This is only noted 

 as an example of what can be done, for in ordinary establishments a 

 piece of board 8 or 9 inches wide, slicing in two grooves outside the 

 house opposite the pipes, is sufficient for ventilation beneath the 

 stages, though iron or wooden hinged bhutters are also employed. In 

 one place I have seen the following method adopted : a channel runs 

 down the side of the path under the pipes, communicating with a 

 small chamber cutbide the house [covered with a grating. The 

 channel opens into the house by several apertures, which can be 

 opened or closed by small lids, and the cold air thus admitted ascends 

 directly to the pipes, being partially warmed before it conies in contact 

 with the plants. The outside grating can also be covered when necessary. 

 Roof ventilation can be accomplished in various ways according to 

 convenience, but for all warm houses, especially in cold bright weather, 

 it is advisable to have pieces of tiffany stretched across the opening 

 to break the force of the cold current. During the winter whenever 

 the wind is keen or frost severe never ventilate, and in very hot dry 

 weather it is better to shade wel 1 , employ no fire hear, damp 

 liberally, and ventilate but little. Without artificial heat the tempera- 

 lure of all but f'.e typical cool houses may be allowed to rise 

 considerably above the maximum temperatures given in the table 

 without danger if waler be abundantly hupplied. For this reason 

 the houses may be closed at 3 to 5 P.M. according to the season and 

 the weather, but a little all-night ventilation in the height of summer 

 will not ba hurtful to tropical Orchids, and for the others it should 

 be the lule at that time of } ear. 



The ordinary roller blinds are the most convenient for shading 

 purposes, as they can be quickly run down or up according to the 

 weather. A very convenient form of blind is the Parisian chain 

 blind, which is formed of narrow strips of wood a short distance 

 apart, so that, while effectually breaking ihe f^rce of the sun's rays, 

 they do not darken the house. These are giving satisfaction in 

 several Orchid-growing establishments. For OdontogLssiim houses 

 in sunny positions permanent shading is sometimes applied to the 



