74 



DEEP BOREHOLE SURVEYS AND PROBLEMS 



of Nordhausen. It is essentially a double-gimbaled pendu- 

 lum apparatus. It is screwed to the upper part of the core 

 box and carries indicating needles which are fixed in posi- 



FiGS. 38 and 39. — Lapp's core 

 orientator. 



Fig. 40. — Koerner's core orientating 

 apparatus. 



tion by dropping in a weight and releasing a fixing device 

 which forces pointers into a cork disc. Like his deviation 

 device, it shows the dip in amount better than direction, 

 the latter being obtained by computation. The pipe drill 

 and core barrel are orientated out of the well by measuring 

 each stand. Figure 40 shows the apparatus for aligning 



