Robert Hooke was one of the great encyclopedic polymaths of 17th-century science. As a founding member of the Royal Society, Hooke made foundational contributions to the fields of astronomy, biology, chemistry, engineering and architecture. His work with springs led to the articulation of what became known as "Hooke's Law," which describes the principles of elasticity
Inspired by the reports of microorganisms from Leeuwenhoek, Robert Hooke began a series of observations through a microscope of his own design. These observations culminated in 1665 with the publication of "Micrographia," Hooke's compendium of observations of microscopic life. Hooke also developed the cell theory of biology from these investigations after observing plant cells for the first time. He was the first scientist to examine fossils through a microscope, and he showed conclusively that they were of biological origin, which was then a minority opinion.
Shortly after the publication of his book, Hooke became the Chief Surveyor in the reconstruction of London after the great fire. To the end of his life, he served as the Gresham Professor of Geometry at Gresham College in London and worked as the Royal Society's curator of experiments. His practical innovations include the iris diaphragm, the respirator and the balance spring.