(micro means 'small' and scope means 'to see' = to see small things)An 'optical microscope' uses two sets of lenses to make things appear much larger than they are in fact…sometimes hundreds or thousands of times larger. When things are made to appear larger than they are, we say they have been MAGNIFIED. A "compound microscope" magnifies things in two stages. Light from a mirror reflects through objects, which must be very thin for the light to pass through them. The light passes into a strong, powerful lens called the objective lens. This is the first time the object has been enlarged. There is also an ocular lens through which you look, this gives the second magnification. This lens is a bit like a small magnifying glass. (Image from http://www.microscope-microscope.org/basic/microscope-parts.htm) There are also modern microscopes called electron microscopes that can magnify up to 300,000 times. What can be seen with an electron microscope is clearer than using a compound microscope. So who invented the microscope? It wasn't just one invention or one person, it was developed over a period of time... The first basic microscope wasn't made until the late 1300s. Two lenses were placed at opposite ends of a tube. This simple magnifying tube was the beginning of the modern microscope. More than 400 years ago in Holland, there was a man who made his living by grinding glass to make eyeglass lenses. His name was Zacharias Jansenn. He noticed that some of his lenses made things look bigger and when he put two lenses together things looked much bigger. So around 1595 Jansenn built the first microscope. Jansenn's microscope consisted of three tubes inside each other – like a telescope – with lenses inside. It had an ocular lens and... half the paper... In 1729, Chester Moore Hall developed a special lens called an achromatic lens and the quality of microscopes improved because the light rays were more controlled and concentrated.image taken from http:// zeiss-campus.magnet.fsu.edu/articles/basics/historical.htmlBibliography http://www.andrewlost.com/microscope_inventors_k3.htm http://www.kidsbiology.com/biology_basics/cells_tissues_organs/cell_history_discovery3.php http:/ /www.history-of-the-microscope.org/hans-and-zacharias-jansen-microscope-history.php http://www.history-of-the-microscope.org/history-of-the-microscope- who-invented-the-microscope.php http://www.microscopemaster.com/history-of-the-microscope.html http://www.microscope-microscope .org/basic/microscope-parts.htm http:/ /zeiss-campus.magnet.fsu.edu/articles/basics/historical.html Science Encyclopedia Parker,S (ed.) Parragon 2000 page132