Barometer

• 1). Roll a pea-sized piece of modeling clay into a ball and stick it in the top of a clear drinking straw. Place the drinking straw parallel to a wooden ruler with the modeling clay at the top of the straw. Wrap tape around the ruler and straw to secure them together.
  
  
• 2). Stick a piece of modeling clay to the inside of the lip of a glass jar. Press the back of the ruler into the clay so it stands straight up in the jar. The bottom of the straw should sit slightly above the bottom of the jar.
  
  
• 3). Fill the jar about ¼ full of water. Drip a little food coloring (your color choice) into the water. When pressure rises, the water will rise up inside the straw. When pressure is low, the water will be low in the straw.
  
  

Thermometer

• 1). Remove the screw-top plastic lid from a glass jar and drill a hole in the center of the top large enough to accept a straw. Slide the straw about halfway into the lid and secure it by squishing clay on top of the lid, around the straw.
  
  
• 2). Fill your jar about half full of rubbing alcohol and drip some red food coloring into it. Screw the lid onto the jar. Make sure the straw doesn’t touch the jar’s bottom.
  
  
• 3). Place the jar somewhere warm or cool. The alcohol should rise through the straw in warm temperatures and sink in cool temperatures.
  
  

Anemometer

• 1). Sharpen one end of a ¼-inch dowel rod in a pencil sharpener. It should look a bit like a garden stake.
  
  
• 2). Poke a bamboo skewer through the side of a paper cup, through the inside of the cup and out through the other side. Slide the cup down to the blunt end of the skewer and stick a second cup on the skewer so there is one cup at each end. Repeat with a second skewer.
  
  
• 3). Cross the skewers so they form an X and place the center of the X over the unsharpened end of your dowel. Carefully tap a thin finishing nail through the center of both skewers and into the top of the dowel. Drive the nail about halfway into the dowel so the skewers spin freely.
  
  
• 4). Drive the dowel rod into the ground in a windy spot outside. The wind will spin the cups at different speeds, showing you how fast or slow the wind blows.