A weather house
Changes in the amount of water vapour are in the atmosphere can be indicated by variation in tension in a few strands of human hair or by using the hygroscopic properties of a piece of catgut.
The familiar weather house can be constructed from cardboard. One end of the gut is glued to a piece of cork on the roof angle; the other end carries a horizontal platform on which figures can be mounted. Two sides of the house should be open to stop heat accumulation, and the outside should be painted white.