A hydrometer is an instrument that measures the density or heaviness of water compared to other solutions. You can make your own with just a few simple materials, but be patient, as it may take a few trials before you get your instrument to float properly.
Things Required:
A straw
Scissors
Small piece of clay
Salt
A glass 3/4 filled with water (to test a hydrometer)
Directions:
Cut the straw in half. Close one end of the halved straw with the clay and form it into a small ball. Pour a small amount of salt into the top of the straw to weight it. The salt should rise about a half-inch in the straw. Hold the straw up to the light to see the level.
Now gently and carefully, lower the hydrometer into the water. It should float freely and straight up, and should not touch the bottom of the glass. If the straw does not float correctly, straight in the water, adjust the salt in the straw or the water in the glass until it does.
