When I used to run my glassblowing business,
I made these by the dozens to give to my students. This style
of microscope is a neat item to have "out in the field"
with students as you are collecting samples of pond water.When I used to run my glassblowing business,
I made these by the dozens to give to my students. This style
of microscope is a neat item to have "out in the field"
with students as you are collecting samples of pond water.
T o make this simple microscope you will need a torch. I used a glassblowers' torch; but a propane hand torch will do the job. The end of a clean length of pyrex 8mm tubing is heated until it is molton. With forceps the molten end is pulled off as the tubing is evenly rotated in the flame. This makes certain that you have a clean end for forming the lens. Continue to heat the end until it rounds over into the shape shown at the left. This will give you a plano-convex lens at the end. You might want to experiment with lightly blowing into the tubing to cause the lens to be slightly concave on the inside surface. Or you might want to try sucking lightly on the tubing to "draw the lens" up into the tubing forming a double convex lens. The shape shown gives good magnification with a convenient focal length. This allows the microscope to be held farther from the eye when in use.
After the glass cools down, you can score the tubing about 30mm from the tip and snap it off. The ends can then be either ground smooth or fire polished.
In use, a drop of water to be examined is placed into the glass tubing microscope (use an eye dropper). By looking up into the lens, you will be able to see items in the water sample move in and out of focus.
If you have no pond, you might try this:
Grab a handful of grass and place it into a beaker (or jar) with a small amount of water. Let this mess sit for a couple days (add water as needed to keep it from drying out). At the end of that time, check out a sample drop with the little microscope. Be certain to get your sample from down within the wet grass.