Editor's Note: It is appropriate for the geophysical community this year to remember the work of G. M. B. Dobson, a pioneer in atmospheric ozone research, on the 100th anniversary of his birth in 1889. A recent resurgence of interest in depletion of stratospheric ozone and the role of chlorofluorocarbons has been sparked by the report of Farman et al. , who found a steady decrease in the October mean total ozone concentrations over Antarctica since the 1970s, from ∼300 to ∼180 Dobson units (1 Dobson unit = 1 matm cm of ozone). A special session A07, entitled “Ozone Depletion in the Polar Stratosphere” will be held at the 1989 Spring AGU meeting in Baltimore, Md. The paragraph below from Dobson  was brought to our attention by M. Nicolet, Brussels, Belgium.