Wegener also noted that the continents move up and down to maintain equilibrium in a process called isostasy. As an example he cited the sinking of Northern Hemisphere lands under the weight of continental ice sheets in the last ice age, and their rise since the ice melted some 10,000 years ago.
Drill that is fitted with a Pipe provides effective connection to the rig surface equipment or application with the bit and the bottom hole assembly for the purpose of pumping the Drill fluid to the bit.
28 Feb, 2008 who invented 0. 1  Drills are very useful tools, commonly used in woodworking, metalworking, DIY projects and construction. 2  Who Invented the Drill. 3  Five Interesting Facts about Drills. 4  Fact 2: Cordless drills utilize rechargeable batteries to allow the drill to be used far from an electricity point.