The compound microscope, a tool that revolutionized our understanding of the microscopic world, was invented around 1590 by Dutch spectacle makers Hans and Zacharias Janssen, who placed lenses in series inside a tube, discovering objects appeared enlarged. 

Here's a more detailed look at the history of the microscope:

Early Development (1590s):

Hans and Zacharias Janssen, a father-son team of Dutch spectacle makers, are credited with creating the early compound microscope, placing lenses in a tube and observing enlarged images. 

They discovered that objects placed near the end of the tube appeared enlarged. 

This invention served as a precursor to both the compound microscope and the telescope. 

Galileo Galilei's Contribution (1609):

Galileo Galilei developed a compound microscope with a convex and a concave lens. 

He also discovered that he could focus his telescope to view small objects close up. 

First Use of the Term "Microscope" (1625):

Giovanni Faber coined the name "microscope" for Galileo's compound microscope. 

Robert Hooke's "Micrographia" (1665):

English physicist Robert Hooke published "Micrographia," which included drawings of hairs on a nettle and the honeycomb structure of cork, using a simple, single-lens microscope. 

He coined the term "cells" when describing tissue. 

Antoni van Leeuwenhoek's Contributions (1632-1723):

Antoni van Leeuwenhoek, a Dutch tradesman, became interested in microscopy and made simple microscopes, discovering objects invisible to the naked eye. 

His microscopes could magnify up to 270x, allowing him to view tiny animals, blood cells, yeast, and even bacteria. 

The Electron Microscope (1930s):

Ernst Ruska and Max Knoll created the first electron microscope in 1931, which could surpass the magnifying limits of the optical microscope. 

Ernst Ruska won the Nobel Prize in Physics in 1986 for his work on the electron microscope.