THE BOOK OF NATURE STUDY 



own observations have shown how the sun stops its upwards rise, 

 and turning, begins once more to descend, the days shortening as 

 he does so. Let them note at the same time that our hottest 

 weather comes after the sun has turned and is beginning to descend, 

 the earth having been warmed by the long days of early summer, 

 whose heat accumulates, as it were, and gives us the blaze of 

 full summer. 



The altitude observations should be continued into winter 

 whenever the weather permits, so as to give some numerical idea 

 of the difference between the summer and the winter conditions. 

 Thus at London the noon altitude at midwinter is only 15, while 



ZENITH 



SUMM PR SOLSTICE 



INTER 



SOLSTICE: 



FlG. 7. The noon altitude of the sun at Kirkwall at the equinoxes 

 and solstices. Compare wtth Fig. 3. 



it is 62 at midsummer, differences which even rough school 

 observations should make clear. Even if it is not considered 

 desirable to attempt to obtain exact figures, the experiments 

 should be so performed as to enable the children to distinguish 

 by them between the summer conditions when the sun is high 

 in the sky, and the winter ones when it is low. 



