16 



but only to loosen the connecting screw and to slide the cap 

 back to the extreme end of the slot in the plane-iron, tightening it 

 there by a turn of the screw. The cap-iron will then serve as a 

 convenient handle or rest in whetting or in grinding. 



The iron lever c (Fig. 23) is held in place below its center by 

 the screw ^, which acts as a fulcrum, and the lever is readily 

 clamped down upon the irons by the use of the cam-piece d. 

 When this cam is turned upward it ceases to bear upon the irons. 

 The lever c may then ' be removed from its place, and the irons 

 released, without turning or changing the adjustment of the screw 

 </, as the lever and irons are properly slotted for this purpose. 



Should the pressure required for the best working of the plane- 

 iron need changing, it .can easily be obtained by tightening or 

 loosening the screw g. 



"\Vhen the plane-iron is secured in its place, the use of the 

 brass thumb-screw Swill draw or drive the plane-iron ; and thus 

 the thickness of the shaving to be taken from the work can be 

 regulated with perfect accuracy. By the use of the lever e, located 

 under the plane-iron, and working sidewise, the cutting edge can 

 easily be brought into position exactly parallel with the face of the 

 plane, should any variation exist when the iron is clumped down. 

 To ascertain this, hold the plane up, and look down over its face; 

 the greater projection, if there be any, of one or the other of 

 the corners of the iron, can readily be seen. 



The cap-irony, which is not sharp, is not, as is often supposed, 

 used for the purpose of strengthening or stiffening the cutting 

 iron, but as a chip-break to prevent the cutting edge of the 

 plane-iron from chipping, tearing, and breaking the grain of the 

 wood below the surface when the grain turns and twists, or when 

 it is knotty and crooked. In such cases the tendency of the 

 plane-iron is to split and tear out the fibres of the wood in front 

 of the cutting edge. To avoid this, the cap-iron is screwed on with 

 its dull edge quite close to the cutting edge, so as to bend and 

 break off the fibres or the shavings before the split gets fairly 

 started below the surface. 



The cutting edge of the plane-iron is said to have lead in 

 proportion to the distance it is placed in adrMnre of the dull ed^r 

 of the cap-iron. The depth of the splits, or the roughness of the 



