This is a replica of Antonie van Leeuwenhoek's microscope made from cardboard, bamboo skewers and a lens made from a pen light.

Antonie van Leeuwenhoek's microscope enabled him to see single celled organisms which he called "animalcules" and helped earn him the name "the Father of Microbiology".

Step 1: Material:

Cardboard (from cereal boxes etc.)
Corrugated cardboard
Bamboo skewers
Light bulb from penlight (not an LED!)
Paint
Tape
Glue
Template (the template.pdf file)

template.pdf
Download

Step 2: The Lens

Van Leeuwenhoek didn't invent the microscope nor did his microscope have the best design, as there were compound microscopes already available at the time. What made Antonie van Leeuwenhoek's microscope special was the lenses that he use. He was able to obtain a magnification of 270 times using small glass spheres that he ground and polished himself.

There are a couple of options to make the lens for this microscope, one is to make a glass sphere much the same way as van Leeuwenhoek did himself. Since I didn't actually use this method myself, I'll give you a general description and point you to a couple of websites with more information. Here and here.

Glass sphere lens

You will need a glass rod and a Bunsen burner.
Grasping the rod at each end, hold it over the flame, as the rod heats up, you should be able to pull the two ends apart stretching the glass to form a thread.
Break the thread in half.
Hold the thin thread of one end of a rod over the flame until it forms a sphere
Break the sphere off from the rest of the thread.

Note: the smaller the diameter of the sphere, the greater the magnification.

Penlight bulb lens
The light bulbs from penlights (pre-LED) have a little lens at the tip to increase the amount of light. If you can get one of these, break the bulb near the base with pliers and chip away at the glass so that you just have the lens and a bit of glass around the sides.

Step 3: Cutting and Folding the Cardboard

Note: This replica is roughly twice the size of the real Leeuwenhoek microscopes.

Placing the templates onto the cardboard, trace and cut out the pieces of the microscope body.
Following the marks on the template, fold the base of the main plate and the stage (focus block).

Step 4: Making the Screws

Cut a bamboo skewer so that you have three pieces one 7.5cm long, one 3.5cm long, and a 3.2cm with the pointed end.
Cut out a small square of corrugated cardboard. Slide the skewer into cardboard along one of the ridges in the centre.
Trim the cardboard so that it looks like a thumb screw.
Do this for the focus knob and the stage height adjuster screw, for the specimen holder I just added a small rectangular piece of cardboard (see picture in step 5).

Step 5: Paint

I use gold craft paint with a bit of yellow added, to give it a brassy appearance. With brown paint I added fake rivets and fake thread on the screws.

Step 6: Making Holes and Taping Boxes

The template file will indicate where to make the holes on the stage and base. I used something sharp to poke a hole and then made it bigger to fit the skewers through. Don't make the holes too big, you want a snug fit so that the skewers don't slip. Note: on the stage, the holes for the focus knob screw should line up so that it can slide through the stage.
Fold up the box for the base and tape together, using tape on the inside.
Fold and tape up the box for the stage, again applying the tape on the inside.

Step 7: Adding Screws

Glue the thumb screw cardboard onto the skewers (you could do this before you paint it).
Glue the specimen holder into the top of the stage.
Glue the stage height adjuster screw into the stage.
DO NOT glue the focus knob, just poke it through the holes in the stage, it should be able to move in and out freely.

Step 8: Adding the Lens

Once the stage is assembled, with a pencil mark where the lens should be placed on the main plate.
Poke a hole and make it large enough for the lens to fit snugly.
Make a hole in the back plate as well (make sure it lines up with the front).
Glue the lens (along the outer edges) onto the main plate and glue the back plate onto the main plate.

Step 9: Using the Microscope

To use the microscope, stick (impale) the object you want to look at onto the pointed specimen holder.
To move the stage, grasp the base with one hand and slided the adjuster screw up or down.
To focus on the object , hold the stage with one hand, with the other, push the focus knob further through the stage, or pull it out to move the stage closer and further away from the plate.
Hold the microscope up to your eye and look through the lens, you may need to move the microscope closer or further away from your eye to see the object through the lens.