Then out came the shovel and some sand from the shed. What’s that in that packet? asked Mair. It’s cement, said her father.

If you mix two parts of sand with one part cement and then add water, you can make cement that’s strong, that will hold the stones together to build a wall. Then he took a bucket of water and put it by Mair’s side. Then he took two parts of sand and one part of cement on the shovel and mixed them together on the ground, and then made a hole in the middle.