Continental drift my lecturers why he was not talking to us about continental drift and I was told, sneeringly, that if I could prove there was a force that could move continents, then he might think about it. The idea was moonshine, I was informed." As late as 1953 – just five years before Carey introduced the theory of plate tectonics – the theory of continental drift was rejected by the physicist Scheidegger on the following grounds. From the 1930s to the late 1950s, works by Vening-Meinesz, Holmes, Umbgrove, and numerous others outlined concepts that were close or nearly identical to modern
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