188 



DEEP BOREHOLE SURVEYS AND PROBLEMS 



Fig. 127. 



the plumbing frame with the registering apparatus is 

 inserted. Thus one can screw up the casing 

 without nut surfaces and still if needed be 

 able to read the position of the registering 

 apparatus against a guide rod.^ 



The Guide Springs. — The longitudinal guides 

 above and below the cylinder are of steel and 

 ringed at their ends, the rings being rotat- 

 able about the plumbing cylinder. The outer 

 ring can be adjusted up and down it. These 

 springs (Fig. 127) must act simi- 

 larly together so that the most 

 outer points always lie on a 

 conical surface through the axis 

 of the apparatus. 



The Inclination Measurer. — 

 Figure 128 shows the internal 

 construction of the dip meas- 

 urer. One of the three bars 

 forming the frame has a lamp 

 (4 volts, 0.45 amp.) with a 

 reflecting parabolic mirror h 

 below it (Fig. 128). The side 

 conductor wires leading up from the lamp are 

 well coiled about one another in order not to 

 influence the neighboring magnets. Next 

 above the lamp is a plain glass plate c with a 

 swinging magnetic needle d held by arm e. A 

 Httle above this an adjustable level / is pro- 

 vided with a glass floor on the cover of which 

 a second magnet swings. The glass plate may 

 be removed so that both magnets, oppositely 

 influenced, may give a suitable intersection 

 angle. Above the level on its glass cover are 

 concentric rings 2 mm. apart, then come the 

 lenses g and h (Fig. 128). Some convex 



1 Gliickauf, No. 7, p. 233, Feb. 15, 1908; Mitt. Markschei- 

 derwesen, Heft 9, p. 53, 1908. 



