Robert Hooke, a famous 17th century English scientist, published a book of sketches such as the one above. What recent invention made these observations possible?

Telescope

Graduated cylinder

Microscope

Calipers

I think it is the Microscope. Robert Hooke was a scientist who came up with the law of elasticity, the Hooke's law as well his pioneering work using the microscope to document observations of a variety of samples in his book. Hook published a book Micrographia, an accurate and detailed record of his observations through his microscope.