Spectral distribution of energy from the sun

urements on the spectral energy distribution of direct solar radiation, made in July 1953, at Sacramento P eak, New M exico, altitude 9,200 feet are described . Spectral data a re given for wavelengths extending from 299 to 535 millimicrons for ai r masses 0, 1.0,2.0, and 3.0. A determination of atmospheric transmittance as a function of wavelength results in calculated total amounts of ozone approximating 0.21 centimeter (ntp) as a mean for 4 days during JUly. Preliminary measurements, employing a lead sulfide photoconducting cell, in the visible and infrared spectrum are discussed. On the basis of the spectral ultraviolet data obtained , an estimate of a value slightly exceeding 2.00 langleys per minute for the solar constant is indicated.