The microscope was invented by two Dutch eyeglass makers named Zacharias Jansen and his father Hans in the year 1590. They put several lenses in to a tube and found out that it can enlarge an object by as much as 9 times its normal size and the images were not so clear. The first microscopes were used more as a novelty item rather than a scientific instrument. Galileo Galilei heard of this new invention and made a better microscope. In the late 1600's, Anthony Van Leeunhoek made use of a real microscope. His microscope had a magnification of 270 times, which during those times other microscopes can only achieve 50 times of magnification. This led to many scientific discoveries and people started seeing things in places where they seem to be empty.
Parts of a Microscope:
- Eyepiece lens - It is the lens where we look through, its magnification is usually 10-15 times.
- Tube - This connects the objective lens and the eyepiece.
- Arm - It gives support to the tube and connects it to the base.
- Base - It supports the whole microscope and is located at the bottom.
- Mirror - Used to reflect light from an external light source to the bottom of the stage. This is used to give light to the specimen on the stage.
- Stage - It is where the slides are placed. The stage has clips to hold the slide in place, it has adjustable knobs that move the platform left and right; and up and down.
- Turret or the Revolving Nosepiece - Two or more objective lenses are in this part. These objective lenses can be rotated to change power.
- Objective lenses - There are usually three objective lenses on a microscope. The shortest lens has the lowest magnifying power and the longest one has the highest magnifying power. The longest lens is retractable because it has a spring in it in order to protect it from hitting the slide.
- Rack Stop - The rack stop keeps users from breaking the lens or slide by preventing them to adjust the lens too low. Factories set this and should only be adjusted when using very thin slides.
- Condenser Lens - Condenser lenses focus light to the specimen making images sharper. They are more useful at the highest powers.
- Diaphragm or Iris - The diaphragm is used to vary the intensity and size of the light that is focused to the slide.