352 RECENT DEVELOPMENTS WITH THE CALYX DRILL 



found further to the west. The most marked of these changes 



~ 



is the magnetic property probabl}* imposed by the inetamorphism 

 nduced by the proximity of the granite. On the abandonment 

 of the mines, the district remained for some years undisturbed, 

 a state from which it was aroused early in 1900 by the energetic 

 prospecting operations of a syndicate of Halifax gentlemen, who 

 it is understood control practically all of the ground described 

 above, which may now under the light of recent developments 

 be fairly termed the Torbrook orNjctaux "synclinal." 



Description of Drill. 



A few words may not be amiss as to the parts and working 

 of this drill. It cuts a 4 or 5 inch core as desired, and the 

 satisfactory results attained may be judged by the fact that the 

 writer recently saw several complete unbroken cores 5 inches in 

 diameter and measuring nearly 7 feet in length. An idea of 

 the valuable record secured by such a core is gathered from the 

 fact that they contained slate, quartzite, and magnetite with 

 crystallized geodes of quartz and stringers of calcspar, all 

 dipping obliquely across the vertical axis of the core. 



The apparatus consists of an upright boiler and compound 

 engine (about 12 h. p.), drum, chain and sprocket wheels 

 driving shaft and bevel wheel, rotating device, drill head and 

 hoisting derrick. 



The drill proper consists of the " cutter," a hollow steel 

 cylinder with peculiarly shaped teeth at the bottom, set alter- 

 nately at approaching and diverging angles with its axis. This is 

 screwed to the bottom of the core barrel which is simply an iron 

 tube of the same diameter into which the core passes when cut 



In hard rock, instead of the cutter and core-barrel, the shot 

 bit and barrel, a fifteen foot steel cylinder of the same diameter 

 is used, and under its edges are fed chilled steel shot, and the 

 friction caused cuts the core. 



The drill rods are of 3 in. hollow steel, and are screwed by 

 means of a " reducing plug " into the upper end of the core- 

 barrel. 



