CULTIVATION. 211 



Wirth's trestle system (Fig. 53). The special feature 

 in this is the replacing of the single posts by trestles con- 

 sisting of two poles crossing each other near the top and 

 fastened at the point of intersection. In this case the poles 

 need not be any thicker than ordinary hop poles. To in- 

 crease the rigidity and power of standing rough weather it 

 is advisable to arrange the trestles alternately, so that one 

 set is longitudinal and the other transverse to the direction 

 of the rows. They are joined together by wires running 

 lengthwise and across, and anchored at the sides and ends 

 of the garden ; or the cross wires may be replaced by wooden 

 spars. The longitudinal head wires may run either directly 

 over the rows or midway between them, according to the 

 style of training adopted. The training wires are hooked 

 either into eyes on the head wires or loosely on the latter, 

 and in this alternative are prevented from slipping out of 

 place by small stops of annealed wire twisted round the 

 head wire on either side of the hooks. At picking time the 

 training wires ,are taken down by means of the gathering 

 hook, and laid on the ground. 



Wirth constructed his trestle frames 2,A to 26 feet high for 

 vertical training and 23 feet for training oh the slope. In 

 setting up the trestles care is necessary to prevent hindrance 

 to team-work, and it is also advisable to have the trestle poles 

 about 3 feet longer than the actual height of the frame 

 demands, so that as the bottoms get rotten in course of time 

 they can be sharpened anew and set up again without alter- 

 ing the height of the frame. The cost of trestle frames is 

 about 5d. to 7d. per plant. 



Two other frames made by the same inventor may be 

 briefly mentioned : the 23-feet sloping frame and the low wire 

 frame. The former is somewhat complicated and requires a 

 special modification in the arrangement of the rows, which 

 have to be alternately 72 inches and 40 inches apart. 



