Climatology and conservation in museums

The article is a summary of the results of a questionnaire sent out by ICOM in 1955. It is a comprehensive survey of the effects of atmosphere on museum objects and methods of measuring and controlling atmospheric effects. The subject headings are: 1. The atmosphere (composition, impurities, humidity, temperature). 2. Hygrometry (including local variations of climate outside and within the museum; ideal climatic conditions; mould growth in the tropics; answers to the questionnaire). 3. Instruments for measuring climatic conditions (both relative humidity and humidity of surfaces). 4. Equipment for controlling climatic conditions (humidifiers, and air-conditioners). 5. Control in practice (as applied to museums, historic buildings and repositories; advice on emergency measures; the problem of the budget). An appendix includes tables of recommended conditions given in answer to the questionnaire, monthly averages of temperature and R. H., comparison of exterior and interior conditions, mean annual and monthly temperatures and R.H. in various cities, comparative data on types of apparatus for measuring R.H., the use of silica gel as a desiccant and applications of air-coinditioning plants to museums (the examples given being in Amsterdam and London).