There doesn't seem to me to be too much discussion on prepping and "survivalist" sites about predicting the weather. This is surprising to me. If you are trying to move off the grid, or are preparing for its failure, wouldn't you think that you'd want to learn how to predict the weather instead of relying on the yackidy-yacks at The Weather Channel, or worse yet, those at The National Weather Service?* At the very least you could stop complaining about your local weather guys & gals getting it wrong!
Obviously, this barometer is pretty unsophisticated, and not something you'd want to rely on to predict a tornado or hurricane. (It does not indicate actual air pressure. It only indicates air pressure relative to what it was when the system was set up.) But here's the thing... while you are setting up your self-reliant weather station, wouldn't it be cool to make this "barometer" with your kids? You'd be teaching them a bit of self-reliance. You'd be teaching them some funadmental science. You might even be teaching them some preparedness skills-- if they are old enough to grasp the concept that lower pressure signals "storms-a-coming," they are old enough to make some decisions based on this information.
How to make it? The authors' list of supplies (with some updates) are:
>milk bottle (Ha! Any glass juice bottle should work.)
>broken piece of "rubber" from a balloon (Ha ha! I suspect the quality of ballon rubber has changed in the last 50 years. I'd use a bicycle tire inner tube or some such thing. Maybe a repair kit for an air mattress.)
>paper drinking straw (Do they make paper straws now? Plastic whould work.)
>cardboard & marker
Cover the milk bottle opening with the "rubber"; secure with rubber bands. Spread a strip of glue (not hot glue!) from the center of the opening to one edge & glue the straw down. Calibrate the cardboard, noting what the "pressure" is when you've set this system up. When you & your kid check the system, if the air pressure is lower than when you established the system, the rubber will buldge upward, and the straw pointer will point down. Higher pressure outside the bottle (the air pressure) than in will push the center of the rubber ddown, and the indicator will point up.
Lots more you can do with the youngins. Make a wetbulb thermometer to gauge relative humidity. Learn the various cloud formations and what they can tell you about upcoming weather patterns. Have fun!
*The National Weather Service is part of the National Oceanic and Atmospheric Administration, itself a part of the U.S. Department of Commerce. So no conflicts there. And why is predicting the weather a responsibility of the federal govenment? From the department's web site:
The historic mission of the Department is "to foster, promote, and develop the foreign and domestic commerce" of the United States. This has evolved, as a result of legislative and administrative additions, to encompass broadly the responsibility to foster, serve, and promote the Nation's economic development and technological advancement.
It's a real stretch for me to get from fostering economic development to the federal govenment predicting the weather. But that's a rant for another time.