Curtains over desk cases are a splendid conservation measure which should be retained.


3 Materials expand by a very small amount. For moisturecontaining materials such as wood, paper, bone, ivory, leather,

textiles and paint this effect can be ignored, since swelling due to water is far greater. For brittle, non-moisture-absorbent composite obiects whose parts expand at different rates - for example, enamel in metal cloisons - an unusual change in temperature might be dangerous.