The Trellis. 29 



top wire in the Kniffin training, which is usually 

 No. 10, as the greater part of the weight is then 

 upon the top wire. No. 9 is sometimes used, but 

 it is heavier than necessary. No. 14 is occasion- 

 ally used for the middle and upper rows in the 

 upright systems, but it is not strong enough. The 

 following figures show the sizes and weights of 

 these and similar iron and steel wires : 



The plain annealed iron wire costs about 3 cents 

 per pound, and the galvanized which is less used 

 for vineyards 3*^ cents. Of No. 12 wire, about 

 160 pounds is required per acre for a single run on 

 rows eight feet apart, and about 500 pounds for 

 three runs. The cost of No. 12 wire per acre, for 

 three runs, therefore, is about $15. 



The wire is secured to the intermediate posts by 

 staples driven in firmly so that the wire will not pull 

 through readily of its own weight, but still loosely 

 enough to allow of the tightening of the wires. In 

 other words, the head of the staple should not quite 

 touch the wire. Grape staples are of three lengths, 

 about an inch, inch and a quarter, and an inch and 

 a half respectively. The shortest length is little 



