In the 1630s, when the official debate over Galileo's provocative defense of the Copernican system was starting to heat up again, physical inquiry began shifting its focus to another part of the natural world. It concerned hydraulics, the limitations of siphons and suction pumps to lift water, and the idea that the air of our atmosphere has weight. If true, that idea would have momentous implications for human life. Within seventy years, Europeans would be pioneering the effort to harness that principle of nature as a new source of energy. First steam power and soon thereafter electric power would follow.

Such technological advances could only be harvested by advances in basic science itself. Furthermore, each of these inquiries was rooted in ancient conceptions that had been studied continuously from the time of Aristotle. In the early 1600s, Italy was a leader in hydraulics and in the construction of mechanical devices for lifting water. Some of these mechanical devices were also used to power machines for the grinding and processing of other materials. Vittorio Zonca (b. ca. 1580) had published a book in 1607 with dozens of illustrations of such devices, some powered by water, some by beasts, and some by human agents. It went through many editions. Consequently, Rome had a band of hydraulics experts in the 1630s experimenting with various hydraulic devices. They found the question of why water can be raised hydraulically only ten meters needing an explanation. This problem was mysteriously linked to the question of a vacuum.