The sampling rig is assembled over Hole #8 and is ready to go. In operation, a sliding weight (the 'hammer') is lifted by hand to the top collar and released. The weight then travels down the guide rod and strikes the collar at the bottom (where the wight is now) which drives the coring tube into the earth. The coring tube is hollow and when the sample is complete, the tube is pulled out of the hole with a jack, but the 'core' of dirt stays in the tube. The boring tube is then removed from the rest of the apparatus and the core of dirt is pushed back out of the hollow tube for lab analysis. Voila' you now have a physical profile of the dirt as layered to a depth of 48"!