Experiment 3

Microscope

Materials

·         A converging lens with a focal length of 1 cm or 2 cm (for the objective)

·         A converging lens with a focal length of 10cm or 20cm (for the eyepiece)

·         A plane mirror

·         A piece of cardboard

·         A support

·         Tubes of cardboard

Procedure

1. Place the lens for the objective into one cardboard tube, and the lens for the eyepiece into another cardboard tube.  Make sure that these tubes can move inside of each other.
2. The support should hold the cardboard perpendicularly to itself.  A mirror should be placed on the base of the support, underneath the glass.  The cardboard is there to support the specimin.
3. Attach the ocular system to the support (above the cardboard), so that the eyepiece is on top of the objective.
4. Make a hole in the cardboard with a radius of 1cm.  This will allow light to pass through.
5. When you have your microscope built, take a small onion and cut it.  Take the epidermis and place it on the cardboard; focus on the onion by moving the tubes until you obtain an image.