How to make a thermometer?

How to make a thermometer...?

• How can you make a thermometer with a straw, a thermos with cold iced tea, and a hot plate?

• Answer:

  Insert the straw in the thermos of cold iced tea to a point where it's just off the bottom. Mark the level of the liquid. This level will approximate 0°C (32°F). Put the thermo on the hot plate and heat the tea until it boils. Insert straw in the tea to a point where it's just off the bottom of the thermos. Mark the level of the liquid. This level will approximate 100°C (212°F). Cold liquids are denser than hot liquids so the initial reading will be lower than the later reading. The distance between the two markings is 100°C. Divide into 10 equal segments.