354 RECENT DEVELOPMENTS WITH THE CALYX DRILL. 



duced, and the engine set going. When a sufficient depth s 

 reached the calyx chip-cup is coupled on and the rods success- 

 ively placed between the chip-cup rod and the square 

 rotating rod. 



It occasionally happens that a rod-coupling breaks at a depth 

 below the surface. The portion of the drill above the break is 

 withdrawn, and a threaded cone called a " tap " is inserted on 

 the end of a rod, and screwed into the broken coupling and the 

 bottom portion is withdrawn. 



When the core breaks accidentally it immediately becomes 

 known by the riding motion of the drill, and the drill runner 

 should be on the alert at such a time to prevent much weight 

 being placed on the drill head, as the couplings at once become 

 endangered. 



When it is desired to withdraw or break a core, the motion is 

 stopped, and a heavy flush of water is forced down the drill 

 rods, coarse gravel being at the same time fed with it. The 

 gravel becomes jammed between the core and core barrel, thus 

 holding the former firmly ; the pipe wrenches are now placed on 

 the square rotating rod at the top, and with the aid of the engine 

 a sharp twist is given to the drill, and the core breaks. 



In the event of a piece of the. core splitting off below, and it 

 being found impossible to re-insert the cutter or shot-bit, the 

 chopping-bit, a steel head like a blunt chisel is placed on the end 

 of a rod, and repeatedly dropped into the hole, breaking up the 

 offending piece of rock. 



As little water as possible is used with the. shot, as it tends 

 to waste by depositing it in the chip cup, or bringing it up to 

 the surface. On the other hand, with the cutter in softer 

 rock all the water possible is used. 



Records of Boring. 



Boring was commenced on October 13th, 1900, on the " Ber- 

 teaux " Farm, at Torbrook, the drill being under the charge of 

 Mr. Burnett, the drill company's expert. 



