Just as the telescope revealed hitherto unsuspected novelties on the grand scale of the heavens, so a similar optical instrument, the microscope, proved capable of revealing novelties at the level of the very small. Although the principle of the microscope had already been discussed by Galileo in 1623 in his The Assayer, it was in 1665 that the first real classic in microscopical observation appeared. Robert Hooke's Micrographia garnered much attention for its lavish illustrations, but Hooke's work also promoted the idea that empirical research in the natural sciences could be improved by devising instruments to assist the senses in general, not only that of vision. In these views Hooke echoed Francis Bacon, who also anticipated means of improving the senses. Indeed, Hooke, who was employed by the ­Royal Society as its curator of experiments, responsible for trying experiments when ordered.