724 



SCIENCE. 



[N. S. Vol. XXIII. No. 593. 



in dew-point only 60°, and that in relative 

 humidity only 71 per cent.— ranges not in- 

 frequently exceeded within twenty-four 

 hours in certain desert localities. 



As the record developed, establishing a 

 persistently low diurnal range in tempera- 

 ture with consistent values for moisture, 

 special attention was turned to the monthly 

 means. Semi-daily means (including rain 

 and also cloudiness expressed in tenths and 

 fractions) are given in the accompanying 

 Table II. As shown by this table, the ap- 



Even more striking than the semi-diurnal 

 means are the daily means summarized by 

 months; largely transcribed from the 

 monthly records, these are recapitulated in 

 Table III. As indicated by the table, the 

 mean diurnal range for the one-hundred- 

 day period varied between 20.1° and 24.5° ; 

 and it may be noted that the greatest and 

 least daily ranges in June were 30.4° and 

 13.4°, the absolute range for the month 

 being 40.5°, while the corresponding values 

 for July were, respectively, 28.0°, 13.9° 



TABLE 11. TEMPERATUEE AND MOISTUBE MEANS. 



TABLE III. ^TEMPEEATDBE AND MOISTTIBE SUMMARIES AND AVERAGES. 



proximate mean diurnal ranges in tempera- 

 ture varied from 11.4° to 15.9°, the mean 

 depression of the wet-bulb thermometer 

 from 15.2° to 29.2°, and the relative 

 humidity from 15.9 per cent, to 40.6 per 

 cent. ; ranges suggesting a moderately 

 humid rather than a distinctively arid 

 climate. 



'Approximate values taken from means in this 

 table. 



'Approximate values taken from means in this 

 table. 



•Taken from monthly summaries. 



and 43.8°, and for August 25.0°, 13.0° and 

 36.3°. The psychrometric and humidity 

 means are consistent, and the ranges corre- 

 spondingly low. (The average dew-point 

 and relative humidity computed from the 

 means in the table are, of course, not 

 strictly accurate ; the values corresponding 

 to the means of 88.9° for the dry-bulb and 

 64.5° for the wet-bulb thermometer would 

 be respectively 49° and 25 per cent.) 



Although deemed of only moderate 

 value, the records of precipitation and 



