PRIjSCIPLES IX THE STRUCTURE OF IMPLEMENTS. 77 



Again, hoe handles^ not needing much strength, chiefly 

 require lightness and convenience for grasping. Hence, 

 in selecting from two such as are represented in the annex- 

 ed figures, the one should be chosen which is lightest near 



Fig. 88. 



Wdl-formed fork handle. 



the blade, nearly all the motion being in that direction, 

 because the upper end is the centre of motion. The right 

 hand, at a, acting partly as the fulcrum, the hoe handle 

 should be slightly enlarged at that place. Fig. 89 rep- 

 resents a well-formed handle ; fig. 90, a clumsy one. Rake 

 handles should be made largest at the middle, or where 

 the right hand presses. Rake-heads should be much 

 larger at the centre, and tapering to the ends, where the 

 stress is least, the two parts operating as two distinct lev- 

 Fig. 89. 



a 



Well-formed hoc handle. 



ers, acting from the middle. Wood horse-rakes might be 

 made considerably lighter than they usually are by ob- 

 serving the same principles. The greatest strength requir- 

 ed ^OY plow-beams is at the junction with the mould-board, 

 and the least near the forward end, or furthest from the 

 fulcrum or centre of motion. 



ISTow it may be that the fiirmcr who has had much ex- 

 perience may be able to judge of all these things without 



Fig. 90. 



o 



Badly-formed hce handle. 



a knowledge of the science. But this scientific knowledge 

 would serve to strengthen his experience, and enable him 

 to judge more accurately and understandingly by showing 

 him the reasons ; and in many cases, where 7iew imple- 

 ments were introduced, he might be enabled to form a 



