TROPICAL AND TEMPERATE HOUSES. 81 



tropical plants in the Botanic Garden flourished 

 without the aid of canvas or shade of any kind. 

 Not many years ago, solitary squares of this glass 

 might be seen in the roofs of the old hot-houses, 

 which strongly contrasted with the modern clear 

 glass. My experience with this glass led me to 

 recommend green glass for the palm-house, which 

 was adopted ; but the modern-made green tint does 

 not appear to be so fixed a color as the old Stour- 

 bridge-green." Various kinds of mats and screens 

 will suggest themselves to every greenhouse-owner, 

 and the most convenient things can readily be 

 turned to account. 



As for heating-apparatus, there will be no trou- 

 ble in finding forms enough to select from. It is 

 important to choose one not unnecessarily large 

 for the work it has to do, and yet not so small as 

 to require forcing in very cold weather, or to de- 

 mand attention during the night. Large furnaces, 

 like most bodies of size, are steadier in their work- 

 ing, and can be as well managed to give a small 

 amount of heat as those of less capacity. The 

 writer has used for several years, in his fern-house, 

 a small Whitely hot-water furnace. It has a 

 " shaking " grate ; and has never, even in the cold- 

 est weather, required attention between seven P.M. 

 and seven A.M. Several others of the same pattern 

 have been observed to be successful in their work- 

 ing ; and this form of heater may especially be 



