determining the azimuthal position of the deflection barrel such as the mercury potentiometer described in co pending u s application of jackson m kellner ser no 584 736 filed june 9 1975 entitled drill director referring now to fig4 instrument package 27 is connected by threaded and shouldered connection 115 with pipe section 32 forming part of a string of pipe extending to out of hole drill rig 37 section 32 is the same as all of the other pipe sections 32 of the pipe string so that only one need be described as will be done in more detail hereinafter as many pipe sections 32 are used as necessary to extend the pipe string from instrument package 27 to the mouth of the hole the instruments in instrument container 116 terminate in conductor means 118 conductor means 118 includes a cable bundle of conductors 120 surrounded insulated and sealed by rubber 124 conductor means 118 extends radially through the side of tube 100 and into a position coaxial within hydraulic channel or tube 100 and is held concentrically therein by mount 119 leaving flow annulus 121 for flow of hydraulic fluid conductors 120 terminate in female banana connector 122 female electrical connector 122 extends beyond the pin end.