Because of the First World War, Wegener's book went unnoticed outside Germany. In 1922, however, a third (revised) edition was translated into English, French, Russian, Spanish, and Swedish, pushing Wegener's theory of continental drift to the forefront of debate in the Earth sciences.
A drilling machine, called a drill press, is used to cut holes into or through metal, wood, or other materials (Figure 4-1). Drilling machines use a drilling tool that has cutting edges at its point.
In the conventional rotary drilling process, a drilling bit on the lower end of a drill pipe is turned by a rotary table, boring through layers of rock at several hundred revolutions. Drill collars are used to increase the drilling pressure. Jetting liquid is used to cool the rotary drilling bit and transport the drilling material to the surface. Modern drilling rigs on the other hand work with a so-called top drive suspended by a hoist on the derrick.