190 DEEP BOREHOLE SURVEYS AND PROBLEMS 



which engages in a cog wheel z on the upper roll. If the cur- 

 rent to the solenoid is shut off the core rises and the clutch 

 turns the upper roll one tooth further, thus drawing the 

 paper strip a corresponding piece forward. On interrup- 

 tion of the current the clutch is snapped into the next 

 tooth by a small spiral spring/. The base of the registering 

 device is fitted exactly to the end plate of the plumbing 

 frame. 



The Current Supply. — The conductor wires go from the 

 lamp and solenoid to three concentric measuring rings 

 which are in the cover of the registering apparatus insulated 

 from each other. One of the rings is connected to both 

 the lamp and solenoid. From here on the cable is led 

 into the upper part of the casing and terminates in three 

 spring rods sliding on three rings in the cover of the register- 

 ing device when screwed up. This gives an easy connec- 

 tion between cable and lamp or solenoid. From the rods 

 the cable goes through the neck of the plumb cylinder 

 casing with suitable screw nut tightening and protection 

 from water. It is a three-wire cable, but two will do if a 

 suspension rope is used or rods, and, if there is a reversing 

 device, one will do. 



The Switch. — This apparatus is switched in between the 

 source and the cable roll. It is used for cutting off, inter- 

 rupting, regulating, and reversing the current. It carries 

 a variable resistance in a wooden frame with an ammeter 

 and voltmeter between, which is an attachment for switch- 

 ing in a control lamp in the circuit. The plugging arrange- 

 ment is for closing or reversing the current to either the lamp 

 or solenoid of the plumbing apparatus. There is a press 

 button for the supply to the lamp as well as a moving 

 measuring arm which slides over a toothed measuring 

 plate which has spaces filled with a non-conducting 

 substance. 



A numbered rotating ring is fitted for the number of 

 teeth. The plate is connected to the registering apparatus. 

 If the accumulator is switched in and the arm turned the 

 registering roll turns correspondingly. The functioning 



