148 CULTIVATION OF THE GRAPE UNDER GLASS. 



made of malleable iron, because they are not as rapidly consumed 

 by rust, and are usually less expensive in the first instance. 



Experiments very carefully made by competent men have 

 settled the fact that more heat will be given out by four-inch 

 pipes, in proportion to the consumption of fuel, than by pipes 

 of any other size. In laying down the pipes, they should never be 

 fastened, but every facility should be given to them for motion 

 lengthwise, by laying them on pieces of rod iron placed occasion- 

 ally under them and upon the support upon which they rest. 

 The linear expansion of cast iron is nearly equal to one inch 

 .and three-eighths in every hundred feet, when the temperature is 

 raised from 32° to 212° ; and unless every freedom is given for 

 the motion caused by this alternate expansion and contraction, 

 the joints will very likely become loose and leaky. 



In heating the vinery it is always desirable to economise as 

 much heat as possible, hence it is weU to run the smoke flue the 

 entire length of the house, which maybe done in a " lean-to" by 

 running it along the back wall. 



BORDERS FOR THE VINES. 



If it be designed to force the vines for early fruit, it will be 

 essential, in our climate, that they should be confined to an in- 

 side border. It is impossible to maintain anything like a cor- 

 responding degree of temperature between the root and the 

 branches, if the roots are permitted to run in an outside border, 

 and unless this is measurably maintained it is impossible to pro- 

 duce good grapes. But in cool graperies the borders may be 

 open, and the vines allowed to ramble outside as well as inside. 



In preparing the borders, if the subsoil be a retentive clay, 

 and, as is usually the case, cold and wet, it is necessary to pro 

 vide perfect drainage. To do this thoroughly, the whole of the 

 soil of the size of the intended border, and to a depth of three 

 feet, should be thrown opt, and the bottom made to slope gradu- 

 ally to the front, with a fall of one inch to the foot, and along 

 the front of the border, and just below the edge, a tile drain 



