Miscellaneous Subsurface Methods 563 



instrument is loaded into the barrel with the bull-plug shock-absorber 

 plunger engaging the bottom of the machine. The bull plug is made up 

 tight. Then the assembly is lowered into the well and held motionless at 

 the correct depth. When the surface watch indicates that the picture has 



Figure 286. Preparing to run regular single shot in open hole on sand line. 



been taken (approximately one-minute exposure) the equipment is hoisted 

 to the surface. The instrument is removed from the barrel, and the fikn 

 is developed and fixed in the unloader. The reading of the disc indicates 

 the drift and direction of the well at the depth at which the picture was 

 taken. 



