Vacuum Pump (ca. 1650): While sometimes called an air pump, in the 17th century the invention of a device to mechanically remove air from a container was actually a result of an interest in the formation of a vacuum within a tube. Pneumatic (air) devices of other sorts had been in existence for centuries. Furthermore, discussions on the nature of a vacuum were not new to 17th-century science. In the 4th century B.C.E. the Greek philosopher Aristotle proposed his four-element theory of matter (see CHEMISTRY). As a component of his theory, Aristotle stated that “nature abhors a vacuum,” and proposed that a fifth compound, ether, filled the spaces between the four elements. Greek supporters of atomic theory thought that there was a void between atoms that could not be crossed (see ATOMIC THEORY) and thus could not exist in nature. These thoughts persisted until the time of the Renaissance when the development of experimental science allowed scientists to finally explore the true nature of a vacuum.
The invention of the first mechanical device to intentionally create a vacuum in a container is credited to the German inventor Otto von Guericke. Around 1645, using this pump, Guericke was able to remove most of the air from containers to create a vacuum. He utilized two spheres to demonstrate the power of air pressure. In one experiment, Guericke connected together two fourteen-inch-diameter copper hemispheres, commonly called Magdeburg spheres after the town in which Guericke was mayor. Using one of his pumps Guericke removed the air from the interior space. As the pressure on the inside of the spheres dropped, the air pressure on the exterior held the spheres tightly together. In fact, the pressure was so strong that a team of horses was unable to separate the spheres. When the air pressure was restored,