Robert Hooke invented a watch escapement and realized it could be used in a clock accurate enough to be used to determine longitude.
He invented a machine for cutting gears much finer than could be made by hand.
He invented a tool for measuring the power of gunpowder, and a tool for measuring fine increments of angles, down to the second of angle, for astronomical objects.
He invented the sash window.
He invented a number of other things, some of which were also invented by other people, such as the universal joint.
He did not invent the microscope, which was invented several
decades before Hooke was born.
He invented the microscope in the year 1681.