212 



PEUNING AND THINNING. 



PT. IV. 



to gather the fruit, by placmg the feet against the 

 stem, and the back against a band which includes the 

 stem and the chmber. 



In pruning old and long-neglected trees, the ladder 

 should be placed perfectly upright against the stem of 

 the tree, and tied fast to prevent its being knocked off 

 by the falling branches, or broken by them. If the 

 head of the tree is out of reach, a string may some- 

 times be swung over one of its boughs by a weight, or 

 shot over with a blunt arrow, and by this a rope hauled 

 over. Seated in a loop at one end of the rope, or with 

 one end tied round the thigh, the hands on the oppo- 

 site rope will acquire the mechanical advantage of a 

 fixed and movable pulley; that is, the double rope 

 doubles your power, or, in this case I should say, 

 halves your exertion, and you may raise your whole 

 weight with half the exertion required without a 

 pulley. Let us call this natural pulley the pruner's 

 pulley. It is often useful to reach the 

 head, or to remove dead wood or a de- 

 tached branch on an otherwise branch- 

 less stem, or to make the pruner safe ; 

 and would make a good fire-escape. 



In explanation I attach an engraving 

 from Chambers's excellent educational 

 course, 'Mechanics,' 1837. The writer, 

 however, like others, has entirely mis- 

 taken the principle of this curious mechanical paradox. 

 In mechanics, indeed, no axiom is more certain than 



