270 



clean, smooth hole. D represents an edge view of the extension 

 cutter, separate from the shank 5. The entire auger should not be 

 more than one foot long. Order the end of the shank made 

 round, to fit a hole or socket in the end of the mandrel (see 

 Fig. 124), instead of having it square, because it can be fitted 

 to run true with less work when the socket is round. The 

 next thing will be, 



THE MANDREL, 



which is represented by Fig. 124. Take a round bar of inch- 

 and-a-half iron, eighteen inches long, to the machine-shop, and 

 have two bearings a a turned and polished (see FITTING UP 



FIG. 124. 



THE MANDREL. 



MACHINERY, next vol.), and fitted to two iron boxes ; have the 

 shank of the auger fitted to the end of the mandrel, and have a 

 small hole bored through the mandrel, at the end or bottom of 

 the socket, so that a punch may be driven in to force out the 

 shank of the auger. The shape of the rocket is shown by the 

 dotted lines at the end of the mandrel. Have a fly-wheel I and 

 large pulley c keyed on the mandrel, and have a small bolt put 



