1(^2 



MAINE STATK COLLEGE 



the same place arc rendered comparable. The rehitions of solar- 

 intensity, as distinct from temperatvne of the air to the growth 

 and maturity of crops, are worthy of careful investigation. 

 High solar intensity maintained through the latter part of the 

 growing season has an important bearing upon the complete ripen- 

 ing of vegetables and fruits and likewise upon their keeping qual- 

 ities. From the wide range of observations undertaken by 

 Experiment Stations with radiation thermometers, important 

 deductions may reasonably be expected. I subjoin tables of 

 results from the maximum thermometer and the thermometer for 

 solar radiation, expressed in monthly averages. 



iVIean of readings, Sun Ther 



Mean of maximum temperatures. 



1889. 



May. .June. 



o o 



133.02 134.22 



. 67.85 73.4.5 



July. Aug. Sept. Oct. Mean. 



139..55 

 7.5.30 



137.56 

 73.72 



122.79 105.86 

 71.23 52.78 



128.83 

 69.05 



Excess of 80lar intensity 65.17 60.77 64.25 63.84 51..56 53.08 .59.78 



1890. 

 April. Maj'. .June. .July. Aug. Sept. Oct. Mean 



Mean of readings, Sun Ther.. 119.1.5 119.45 

 Mean of maximum Temp 49..37 61.16 



Excess of solar intensity. 



128.81 

 68.01 



139.37 

 76.53 



138.25 114.94 

 74.67 62.32 



112..52 

 55.61 



124.65 

 64.38 



69.82 .58.29 60.80 62.84 63..5« 49 62 .56.92 60.27 



April. 



1891. 



May. June. 



.July. Aug. Sept. Oct. Mean. 



Mean of readings, Sun Ther. .106.78 119.19 129.44 140..35 129.55 121.85 



Mean of maximum Temp 50.65 



Excess of solar intensity .56.13 



62.48 72.17 76 



75.39 



63.67 .54.16 



69.84 

 51.81 



99..55 120.93 

 54.18 65.91 



45.37 .55.02 



1892. 

 April. May. .Tune. July. Aug. Sept. Oct. Mean. 



O 00 GO GOO 



Mean of readings, Sun Ther.. 113.32 112.47 127.11 1.39.50 128.25 123.82 97.62 120.30 

 Mean of maximum Temp .53.93 62.22 72.87 82.28 75.07 68.74 .5.3.16 66.90 



Excess of solar intensity .59.39 50.25 .54.24 .57.22 53.18 55.08 .44.46 .53.40 



From the above records it appears that the average excess of 

 solar intensity above that given by the maximum thermometer for 

 the growing periods of 1889, 1890, 1891 and 1892 was 57.12°. 



The season of greatest excess in this regard was that of 1890, 

 a season noted for the perfect maturity of fruits and vegetables. 



