Continental drift Continental drift Continental drift is the theory that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed. The speculation that continents might have 'drifted' was first put forward by Abraham Ortelius in 1596. The concept was independently and more fully developed by Alfred Wegener in 1912, but his theory was rejected by many for lack of any motive mechanism. Arthur Holmes later proposed mantle convection for that mechanism. The idea of continental drift has since been subsumed by the theory of plate tectonics, which explains that the continents
Drift pin Drift pin In metalworking, a drift pin, drift pin punch, slave pin, simply drift, or even pokey bit is the name for a tool used for enlarging holes, or aligning holes prior to bolting or riveting metal parts together. A drift pin is not used as a punch in the traditional sense of the term. A drift is constructed as a tapered rod, with the hammer acting on the large end of the taper. The tapered end of a drift punch is placed into the semi-aligned bolt holes of two separate components, and then driven into the hole. As it