In this paper the measurements of the planetary radiation transmitted through a water cell as observed by Coblentz and Lampland at the Lowell Observatory during the summer of 1924 are reduced by Menzel by the method published by him in this Journal in 1923. The results obtained seem to prove quite conclusively that the bright areas are at a lower temperature than the dark areas, and that the equatorial (black-body) surface temperature of Mars at perihelion rises above 0 degrees C. The true temperature, corrected for emissivity, would be about 10 degrees higher. The temperature of the south polar cap was -100 degrees C on August 14, gradually increasing to about -15 degrees C on October 22, indicating that the cap is probably composed of ice and snow. The low temperature of the east limb, which was down to -85 degrees C, is definite proof of an enormous diurnal fluctuation. Various methods of combining the observations give concordant results. The temperature of the moon reached 120 degrees C under perpendicular insolation. The distribution of energy in its heat spectrum is not consistent with a radiating surface of quartz. The temperatures of Jupiter, Saturn, and Uranus are low, the values calculated from the water-cell transmissions being -130 degrees C, -150 degrees C, and -170 degrees C, respectively. There is little evidence of internal heat.