Experimental results on the total radiation clue to carbon dioxide, water vapor, and mixtures of the two that were recently reported were obtained in a chromel-wound furnace, the maximum operating temperature of which was 1850 F. The final plots were obtained by extrapolating to 3600 F the experimental data covering the range from room temperature to the furnace maximum. A method is now described for determining these properties directly in the upper temperature range. It consists of measuring the emission of radiation, and the corresponding temperature, from overventilated flames of carbon monoxide, hydrogen, and mixtures of these in a Meker burner of varying length. The products in the flame are calculated from the mixture fed to the burner. Results are presented for flames of carbon monoxide in mixtures of oxygen and nitrogen in which the burner grid length is varied from 2 to 16 in., the theoretical oxygen from 100 to 300 per cent, and the flame temperature from 2600 to 3800 F. The results establish the validity of the carbon-dioxide radiation chart in its high-temperature range. Less extensive measurements on illuminating-gas flames establish the validity of the water-vapor radiation chart at temperatures of 2500 to 2800 F when the thickness of gas layer is small.