36 ELEMENTS OF GENERAL SCIENCE 



surface. The light and heat coming through the hole might 

 be the same in both experiments, but in the morning they are 

 distributed over more surface and are therefore less intense. 

 If you spread your butter over a larger piece of bread, it 

 will be spread thinner. 



Of course the difference that you have discovered between 

 morning and noon exists between winter and summer. Can 



A.M. 



P.M. 



6 



June 



July L 



Aug. Q 



Sept. [ 



Oct. [ 



Nov. [_ 



Dec. [ 



Jan. [ 



Feb. 



Mar. [_ 



April [ 



May [ 



10 11 12jJ 



ffil 



23456 7 8 9 10 11 It 



or ill g 



1 :.} 



June 



] July 

 ] Au*. 

 ] Sept. 

 ]0ct. 

 ] Nov. 

 ]Dec. 

 ] Jan. 

 ] Feb. 

 ]Mar. 

 ] April 

 1 May 



FIG. 23. Hours of light and darkness 



The proportionate length of time the sun is above the horizon at a latitude of 

 40 N.; the time in which artificial and natural light are ordinarily used; and 

 the effect of the daylight-saving legislation in which / is the time of artificial 

 light now used for sleep and x the daylight redeemed from that previously 

 used for sleep 



you make a drawing showing exactly how large a space will b& 

 covered by a beam of sunlight one inch square if it comes to 

 the earth at an angle of 65 ? of 18 ? In which case would 

 the earth's surface receive more heat to the square inch? 

 How much more? Which corresponds to summer? to winter? 

 35. Length of day and night. In summer, when the sun 

 is higher in the heavens, it is also visible more hours in the 

 day. The difference between the longest day and the shortest 



