The physical and chemical characteristics of atmospheric aerosol were determined at a site remote from anthropogenic influences, on the edge of the Antarctic continent. The number concentration (0.12–3.12 μm diameter) ranged between 9 and 90 cm−3 and the corresponding mass between 0.1 and 3.7 μg m−3. The concentration of sulphate in two filter samples was 0.29 and 0.48 μg m−3. Size distributions at the site were remarkably invariant. The two major factors affecting the size distribution and concentration were occurrence of precipitation and atmospheric stability, respectively.

Improvement of the photographic recording system on the Cambridge Stereoscan Mk IIa is discussed. As well as considering the format and quality of the camera and lens, the importance of correctly aligning the recording cathode ray tube focus is stressed. Other problems which the authors have found associated with the recording system are discussed.