In our Science topic on 'Rocks and Soils' we tested the permeability of different rocks. This is how close together the particles of the rock are, allowing water to get through. The children came up with some good ideas for testing the rocks but we finally went with using a pipette and squeezing water over them and timing what happened with a stopwatch. Most children found chalk, limestone and sandstone to be most permeable. Slate was one of the least permeable.