A novel olefin polymerization catalyst is provided which comprises a transition metal compound or lanthanoid compound containing two or more atoms selected from the group consisting of boron, nitrogen, oxygen, phosphorus, sulfur, and selenium; and a Lewis acid. The apparatus, which is used to provide an output signal that is a function of the difference between two sample signals VS1 and VS2, includes first and second capacitor elements that are coupled together at a common terminal. One method comprises manipulating a casing joint by mechanically gripping an interior thereof, hydraulically gripping the interior of the casing joint responsive to drilling fluid pressure, and rotating the casing joint.