INSTRUMENTS USED IN HORTICULTURE. 139 



use by carpenters. Draw -saws have the teeth formed so as to point to the 



operator, fig. 44, &, and only to cut when 

 the blade is drawn towards him. Thrust- 

 saws have the teeth or serratures formed at 



. right angles to the edge of the blade, so as 



JVyuy//^*// * cut cn i e fly when pushed or thrust from 

 i d c tn e operator, but partly also when drawn 



Fig. 44. Garden-saws. towards him. The draw-saw is always used 



with a long handle, and is very convenient for sawing off branches which are 

 at a distance from the operator. In both these saws the line of the teeth is 

 inclined about half the thickness of the blade to each side, as shown at d; 

 the advantage of which is, that the blade passes readily through the branch 

 without the friction which would otherwise be produced by the two sides of 

 the section. Draw-saws being subjected to only a pulling strain, do not 

 require so thick a blade as thrust-saws; and, for that reason, they are also 

 much less liable to have the blades broken or twisted, and are less expensive. 



412. Pruning chisels are chisels differing little in some cases, fig. 45, e, 



from those of the common carpenter, fixed to the end of a long 

 handle, for the purpose of cutting off small branches from the 

 stems of trees at a considerable height above the operator. The 

 branch should not be larger than \\ in. in diameter at the part 

 to be amputated, otherwise it cannot be so readily struck off 

 at one blow. In performing the operation two persons are 

 requisite : one places the chisel in the proper position and holds 

 it there, while the other, with a hand-mallet, gives the end of 

 the handle a smart blow, sufficient to produce the separation 

 of the branch. If properly performed, the section does not 



Fig 45. Pruning- re( l u i re any dressing ; but sometimes there are lacerations of 

 chisels, the bark, which require to be trimmed off with the hooked 



part, g, of the chisel, /. 



413. Shears, in regard to their mode of cutting, are of two kinds : those 

 which separate by a crushing cut, as in the common hedge-shears, fig. 46, 



the grass- shears, and verge- 

 shears ; and those which se- 

 parate by a draw or saw 

 cut, as in the pruning-shears, 

 fig. 47. The common hedge- 

 Fig. 46. Shean for clipping hedges and box edgings. shears IS used in gardens for 



topiary work, cutting hedges of privet, and other small-leaved slender- twigged 

 hedge-plants, which do not cut so readily with the hedge-bill ; and it is 

 more especially used for clipping box edgings. The pruning- 

 shears, fig. 47, have one blade, which, by means of a rivet, 

 moves in a groove, by which means this blade is drawn across 

 the branch in the manner of a saw, and produces a clean or 

 draw-cut ; that is, a cut which leaves the section on the tree 

 as smooth as if it had been cut off by a knife. There are in- 

 struments of this kind of various sizes, from that of a pair of 

 common scissors, for pruning roses or gooseberry bushes, to 

 such as have blades as large as those of common hedge- 

 shears, with handles four feet long, which will cut off branches 

 from two to three inches in diameter. All of them may be Fig. 47. Pruning- 

 economically used in gardens, on account of their great power, theart. 



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