Direct, real-time gas chromatographic measurements of CF2Cl2, CFCl3, CCl4, and N2O were made at latitudes from 74 ¿N to 62 ¿S aboard a NASA Convair 990 as part of the 1976 NASA CV-990 Latitude Survey Mission between Alaska and New Zealand. A difference was found in the average mixing ratios of CF2Cl2 and CFCl3 between the northern and southern hemispheres, but not differences were noted for CCl4 and N2O. The results support some of the previous studies of interhemispheric tropospheric gradients and suggest the lack of any significant tropospheric sinks.