150 BRITISH MODES OF CULTIVATING 



called the usual form ; they differ from M'Phad's, 

 and the houses built by Speedily, and originally 

 by Nicol, in not having a path in front ; and from 

 those of Mr. Aiton, erected in the royal gardens 

 at Kensington, in the pit being farther from the 

 glass. They are about fourteen feet wide inside 

 measure; the pit is ten feet three inches wide, 

 three feet deep, three and a half feet from the 

 glass in front O), and about six feet and a half 

 behind ( b ). The back path ( c ) is a border regu- 

 larly dug and manured, to encourage the roots of 

 the vines, which pass under the bark bed to the 

 front border. Each house is forty feet long, and 

 has a flue proceeding from the back wall to the 

 front, and along the front to the opposite end, re- 

 turning to the back wall in the usual manner. As 

 the houses are all heated by steam, however, these 

 flues are erected* merely by way of security, in 

 case of any accident happening to the boiler or 

 the pipes ( d, e ), and are therefore seldom used. 

 Besides the vines trained over the back path, there 

 are others which are led up the rafters ; both root 

 into excellent soil, and their shoots are withdrawn 

 in autumn to give them three months' rest in the 

 open air. Those at the back wall are withdrawn 

 through an opening in the angle of the upper sash ; 

 those in front through an angle of the front sash. 



The pits are sunk in the ground to the sill of 

 the sashes in front, and within eighteen inches, or 

 two feet of the sill behind. In all of them, the 

 tan is inclosed by brick walls; they are generally 



