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.
The use of a seed drill can improve the ratio of crop yield (seeds harvested per seed planted) by as much as nine times. Some machines for metering out seeds for planting are called planters. The concepts involved (such as mechanisms that pick up seeds from a bin and deposit them down a tube) are largely the same.