A One-Dollar Compound Microscope
By James Grahame
Everyone should have a microscope, especially if you can get your hands on one for practically nothing. With that in mind, I offer you this link to Giorgio Carboni's Do-It-Yourself compound microscope. It's capable of 75X magnification and even offers fine-focusing. To keep expenses low, he salvaged four lenses from disposable cameras.
Makes me wonder why cheap plastic 'toy' microscopes cost so much in comparison.
Microscopes first appeared around 1600. Some attribute the invention to Galileo Galilei, but the Wikipedia says "Anton van Leeuwenhoek (1632-1723) is generally credited with bringing the microscope to the attention of biologists, even though simple magnifying lenses were already being produced in the 1500's, and the magnifying principle of water-filled glass bowls had been described by the Romans." So there you have it.