How to Build a Barometer Using a Latex Glove

Remove the upper part of the latex glove, cutting just below the fingers. Then cut along the thumb area from the bottom of the glove to the newly-cut edge. You should now have a rectangular piece of latex.

Fit the latex over the top of a clean, dry glass jar and adjust it so it fits snugly without any wrinkles. Fasten it with rubber bands and then trim any excess latex. The air within the jar will be at the same pressure as the air outside of the jar.

Cut the straw in half and tape the toothpick to one end. The free end of the toothpick should extend half its length from the straw. Lay the other end of the straw flat at the center of the latex covering and tape it in place.

Measure a wider face of the brick. Cut a piece of poster board that has the same width as that face, and is 5 inches longer than its length. Tape the poster board to a wider face of the brick, aligning one edge of the length of the board flush with one end of the length of the brick. Stand the brick upright alongside of the jar with the toothpick pointing at, and nearly touching, the poster board.

Draw a line parallel to the top and bottom edges of the poster board at the level pointed to by the toothpick. This line represents the current barometric pressure. Check the position of the toothpick each day and mark its position. When there is a high pressure and the weather is clear, the toothpick will be pointing higher, as the pressure pushes down on the air in the jar. A low-pressure system will be indicated when the toothpick is pointing down, and the air in the jar pushes up into the lower pressure of the surrounding air.