Time-lapse shot of mercury column in standard barometer, of pointer descending and making contact with mercury column. LAMS of technician looking into barometer eyepiece. CU of eyepiece, man looking into it. Shots of Dr Olofson working on ozonesonde equipment at Climatological Section of Meteorological Branch of Department of Transport. Shot of Dr Olofson reaching into ozone generator, taking out ozone sensor. CU of Dr Olofson's hands at work on ozonesonde calibration room at Scarborough research station. CU of Dr Olofson's face as he works. Shot of man at ozonesonde read-out machine. Over shoulder shot of man using calculator, writing down data. Shots of two men at ozonesonde read-out machine. Slow TILT UP ozonesonde read-out recorder and pointer.