EARLY MICROSCOPES
Anthony van Leeuwenhoek of Holland was interested in lenses and worked with magnifying glasses. He became so interested that he learned how to make lenses. His microscopes were able to magnify up to 270 times !
Anthony Leeuwenhoek was able to see things that no man had seen before. He saw bacteria, yeast, blood cells and many tiny animals swimming in a drop of water. From his great contributions, many discoveries and research papers, Anthony Leeuwenhoek (1632-1723) has been called the "Father of Microscopy". Robert Hooke, an Englishman, also spent much of his life working with microscopes and improved their design and capabilities.

MICROSCOPIC PREPARATIONS
Before any microscope observation you need to prepare the sample (also called specimen or objective). As light must go through the sample the preparation has to be transparent.
The most common microscopic preparation utilizes a flat slide (rectangular and thick) and a cover slip (square and thin). To make one:
1. Place a drop of the sample in the middle of a clean slide
2. Put a cover slip gently over the drop
3. Allow the liquid to spread between the two pieces of glass without applying pressure
4. If little liquid is used, the organisms may be crushed by the cover glass and evaporation will dry the specimens quickly
5. A well-prepared slide will last for 15 -30 minutes before it dries up.

COMPOUND MICROSCOPE
The compound microscope uses lenses and light to enlarge the image and is also called an optical or light microscope. The compound microscope has two systems of lenses for greater magnification, 1) the ocular, or eyepiece lens that one looks into and 2) the objective lens, or the lens closest to the object or specimen. Others parts are:
· tube: Connects the eyepiece to the objective lenses
· arm: Supports the tube and connects it to the base
· base: The bottom of the microscope, used for support
· stage: The flat platform where you place your slides.
· revolving nosepiece: This is the part that holds two or more objective lenses and can be rotated to change power.
· condenser Lens: The purpose of the condenser lens is to focus the light onto the specimen. Condenser lenses are most useful at the highest powers (400X and above).
· diaphragm or Iris: it has different holes and is used to vary the intensity and size of the light projected upward into the slide.

HOW TO USE YOUR MICROSCOPE
1. When moving your microscope, always carry it with both hands
2. Turn the revolving nosepiece to the lowest power objective lens
3. Put the microscope slide prepared with a cover slip or cover glass over the specimen
4. Place the microscope slide on the stage
5. Look at the objective lens and the stage from the side
6. Turn the coarse focus knob so that the objective lens moves downward
7. Slowly turn the coarse adjustment so that the objective lens goes up
8. Continue until the image comes into focus
9. Use the fine adjustment for fine focusing.
10. Continue with higher magnification objective