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The Challenge: Make a Microscope

Would it be possible to make a simple microscope on the island?

Despite the fact that there were no clean, unscratched lenses on the island, there is a very simple microscope you can make using a tiny (about 2mm diameter) ball of glass. To get lenses of high quality, the spherical balls need to stay small. The reason why the glass beads are spherical instead of tear-drop shaped is due to surface tension. With small enough blobs of melted glass, the force of surface tension keeps the balls round. Once the balls get too big, gravity starts to deform the spheres into drop shapes.

WARNING: It is essential that you wear eye protection when using a flame and working with glass.


Animation of heating glass rod
  • We heated the central part of the glass rod until it looked like it had softened.

  • We removed it from the flame and pulled it firmly apart until it was very thin.

  • We broke the thread using tweezers.

  • We held one of the threads horizontally in the flame until it began to melt, forming a little ball.

  • We rotated the thread in the flame until the ball reached 1.5 to 2mm (0.06 - 0.08 in.) in diameter.

  • We then removed the thread from the flame and let the ball cool. When cool, we broke off the thread about 10mm (0.4 in.) from the little ball using the tweezers. We used the tail to glue the lens in its seat.

  • It took us a few tries to get a glass bulb without air bubbles or other imperfections.