Note on the measurement of ozone in the atmosphere

The absorption coefficients of ozone for ultra‐violet wavelengths which have previously been accepted as correct, do not agree with measurements made on the ozone in the atmosphere. New laboratory measurements are now reported, in which the same spectroscopic apparatus is employed as is used in the atmospheric work. The absorption coefficients so found agree well with the atmospheric values. The possibility that there may be other gases in the atmosphere, in addition to ozone, which absorb in the ultra‐violet region is examined. Only sulphur dioxide might possibly give trouble but the amount present is too small to cause appreciable errors in the ozone measurements.