By using this kit (one Two-Hole Connector and two Clear Plastic Tubes) in conjunction with two plastic 2-liter soda bottles (available wherever soda is sold) you can demonstrate Vacuum and Compression principles. Hero of Alexandria in 62 A.D. described a water fountain that used compressed air to lift water to a point higher than its origin. A close study of your demonstration will reveal the principle of this operation. Complete background instructions and ideas for a vacuum and compression are on the back of the package.