TEMPERATURE 17 



absolutely necessary, and work it at low pressure, than to 

 have barely sufficient power and work it hard during severe 

 weather, as the heat diffused in the latter case is harmful. 



Before deciding on the means of heating to be employed, 

 it would be well to pay a visit to some of the collections 

 noted for the excellent condition of their plants, and inspect 

 the appliances and their arrangement. Most Orchid growers, 

 whether in private establishments or nurseries, are willing to 

 assist amateurs in these matters. When the apparatus has 

 been got into working order, tests should be made to 

 ensure an equal distribution of the heat from the piping. 

 If a draught of hot air to any part of the house from be- 

 neath the staging is observed, it is a good plan to build 

 up openly-laid screens or brick walls 4! inches thick, the 

 layers of brick being placed so that there is half the length 

 of the brick opening between each brick and the next to it. 

 Where there is a sufficient command of heat, these openly- 

 laid brick walls, without mortar, built up below the side 

 staging and running parallel with the edge of it, if they are 

 syringed frequently, assist materially in preserving a healthy 

 moisture in the house. 



TEMPERATURE 



One of the most important matters in Orchid cultivation 

 is to see that a lower temperature is maintained at night 

 than in the day. Nothing is more injurious to the plants 

 than to be kept in a high temperature at night, nor is 

 anything more contrary to natural conditions. All who have 

 travelled in the countries from whence Orchids have been 

 imported testify to the great difference between the tempera- 



B 



