Images of robert hooke microscope

Commentary
Images
Resources

Commentary

For his observations, Robert Hooke made use of a compound microscope designed by the London instrument maker Christopher Cock.

The first compound microscopes were developed by Galileo and Giuseppe Campani in Italy (1624-1625), and featured three lenses: a bi-convex objective lens placed in the snout and two additional lenses, an eyepiece lens and a field lens fitted in the tube.

Cock's design followed this basic Galilean model. The three of the lenses together offered a good view of a sizeable object, but Hooke found that the resolution was poor:  

The Microscope,... was contriv'd with three Glasses; a small Object Glass..., a thinner Eye Glass..., and a very deep one...: This I made use of only when I had occasion to see much of an Object at once; the middle Glass conveying a very great company of radiating Pencils, which would go another way, and throwing them upon the deep Eye Glass.

To obtain better resolution, Hooke had to remove