20 ELEMENTARY WOODWORKING 
is necessary to follow this jack plane with a finer one 
having a straight edge in order to smooth the surface. 
The jack plane might be called a roughing plane. 
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Fie. 24. Relative Sizes of Smooth and Jack Planes 
The lower figure is a jack plane 
11. The Smooth Plane. The smoothing plane is shorter 
than the jack plane, its object being to smooth the sur- 
face without regard to straightening it, as it 1s supposed 
that the straightening has previously been done. The 
