A Miniature Diving Bell
You will need: Handkerchief, water glass, bowl of water.
Scientists have explored great depths of the sea by being lowered in diving bells. Usually air is pumped down from the surface, although some bells have compressed air cylinders.
It is possible for us to make a miniature diving bell from an ordinary upturned water glass.
First, roll a handkerchief into a ball and wedge it tightly into the bottom of the glass. Turning the glass upside down, make quite sure that the handkerchief remains in position. Then push the glass vertically into the water, and keep your hand on top of the glass so that it does not overturn.
Remove the glass from the water and retrieve your handkerchief-it is still perfectly dry! The reason for this is the fact that air trapped in the glass, as it was lowered below the surface, prevented water from entering the tumbler.
Children learn best through doing
Before children can understand a thing, they need experience: seeing, touching, hearing, tasting, smelling; choosing, arranging, putting things together, taking things apart. Experimenting with real things.
Old-time school teaching used only words and the teachers thought children knew something if they could repeat it. Now we know better. To reach practical understanding we do not need to use many words with young children.
Children are clever. They learn a lot, without being taught. The greatest skill - to be able to talk, to communicate is learnt outside school. In the classroom it's the children who need to talk the most. Unfortunately it is the teacher who does most of the talking!