This papr r co nlain information relatin g to t hg setting L~P <;>f s lalldarc~ b lackbodi es [~r use t hro ug h t he te mperat ure range of abo ut 1,400 to 2,400 h and then use In the caIJbration of tungste n strip lamps as Iaboratory .stand a rds of spectral . rad Ia nce fO I· t he lVit;-relength regio n of 0.25 to 2.6 mi crons. A gml?h lte b lackbody IS d esc n bed a nd rep rese ntatlvr data a re gi ven on the spec tnd c ha racte l'ls tlCs of the new lamp standard as compared to b la ckbodies at se veral se lec ted temperatu res.

Spectl'oradiometric measurements of the distribution of direc t solar radiation at Sunspot, New Mexico (altitude 9,200 feet). in June 1955 are d escribed. Detailed spcctral data were obtained within the spectral range of 299 to 535 millimicrons for different air masses. At longer wavelengths radiant-energy evaluations ,rere made only for selectcd points between the water-absorption bands.From these data, supplemented by other measurements and estimates for radiantenergy intensities for very s hort and very long wavelengths, a preliminary spectral integrat ion of the total solar intensity yields a solar constant in general agreement wiLh the best published values.

An au tomatic photoelectric instrument and method for t he continuous meas urement of t he ozone in the earth's atmosphere at low altitudes are described. The method is physical rather t han chemical in character and is based upon t he optical absorption characteristics of ozone in the Hartley and Huggins ul t raviolet bands. Th e ins trument makes use of a lowpressure mercury are, which is situated at a di stance of 1,450 feet from the reco rding s tation t hat emp loys a 1P28 photo mult iplier as a d etector . The lig ht beam is modulated, at 510 cycles per se cond, so that the output of t he photomultiplier is fed into a t uned alternatingcurrent ampllfier and amphfied to the recorder level. By means of a Geneva m ec han is m which changes t he glass filters, the radiant energy from t he lamp is separated into band~ primarily at wavelengths 253 .7, 365.5, a nd 405 .0 millimi cro ns. From the ratios of the de1kctions for t he different spectral regions it is possible to d etermine ozone concentration in t he range from a few te nths of 1 part to many p ar ts per 100 million.

M eas 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.

R es ults ar e g iven of som e measureme nts on t he ultraviolet and s hort-wa velengt ll visi ,b le s ect ral radian t energy reflected from t he surface of the full moon , made from Octobe r to ~ rnber 1952 at Wa shington D , C. Although t he reflected lunar spectrum co nta rn s a ll th~eFraunh orer' bands as found in ?irect sunli ght .wi th approximately t he s ame r~e laLr ve in tens it ies in t he visible spectrum , In tense ab so rp t r~n occu r's for so me. of the ult rav iolet wavelengths. Selecti ve absorp tion for wavele ngths III the spe?tT1!-l reg ron s of 380 to ~9 0 millimi crons and less t han 360 millimi crons indi cates t he pOSSIbility of a lun ar re flect rn g s urface s imi la r to t ha t of powde red glassy silicates.