To make a cloud in a bottle get a 2 litter bottle and place it into some water. Blow air into the bottle and seal with the lid. Then you need to give it a good shake. Take a match light it, let it burn for a few seconds and drop it into the bottle. Lay the bottle on its side on a dark background. Push down on the bottle then release. You should have a cloud! If not push and release again. Be careful with the matches!