148 BEAUTIFUL FLOWERS 



house. You can call it a glorified frame or an abbreviated green- 

 house, whichever way you like to look at it. It is generally con- 

 structed partly of bricks, on a few courses of which a low frame is 

 fixed, with sliding lights. Such a structure is often established 

 under a greenhouse, running the entire length of it. Its uses corre- 

 spond to those of a frame. It generally has the advantage of being 

 a little more roomy, but the disadvantage of not being movable. 

 Sometimes, however, a pit becomes much more than a large fixed 

 frame ; it becomes neither more nor less than a small sunk stove. 

 Hothouses below the ground level are generally spoken of as " pits" 

 in gardens. They are serviceable for special purposes, such as the 

 cultivation of Cucumbers and ferns, but not for all-round use in 

 growing flowering plants ; and amateurs need not trouble about 

 this class of structure. 



Glazing. It is wise to use 2i-ounce in preference to i6-ounce 

 glass for all kinds of glass structures, as the greater cost is not 

 excessive. Top putty should be avoided. The squares should be 

 bedded in putty, and then fastened in with small sprigs. 



Heating. When we come to consider plants for glass structures 

 of different classes we see that it is possible to find some pretty 

 flowers that will thrive without artificial heat, but only where ex- 

 pense is a great consideration, or time for attending to a heating 

 apparatus very limited, should a house be left unheated. Want 

 of heat limits the owner severely. He may be without flowers for 

 several consecutive weeks if the winter should prove to be a severe 

 one, and he cannot command a supply at any particular period. 

 Moreover, there are many beautiful plants which he cannot attempt 

 to grow at all. Heat the house, therefore, if it can possibly be done. 



Large houses are heated in almost every case by a hot-water 

 apparatus, consisting of a boiler and pipes. Boilers differ consider- 

 ably, but pipes very little. The boiler may be an upright or a hori- 

 zontal one ; it may be plain or tubular. The pipes will be of cast 

 iron, and will be four inches in diameter. An upright boiler let 



