At Camp Green Lake water is a precious commodity. So when the children used water to help separate salt and sand, the warden was not pleased about being left with salty water. After some research the children decided they could leave the water to evaporate and that would mean they could return the salt to the kitchen. But once again the warden wasn’t happy. The children had to work out a way of separating the salt and water without loosing any of it.
The children worked out they needed to evaporated the water and then condense it again by cooling it down. They used a cooker to heat the salt water. Then a metal plate and ice block was put on top. After a little while, the plate was lifted and the condensed water dripped into a clean container. Left in the pan was the salt.