Fogs and Clouds 113 
readily classifiable; for instance, you may not be able to 
decide to what category a certain cloud belongs. 
' This is not to be regarded as a lack of ability on your part, 
or as a failure of science. It is merely a borderline case—one 
of the constant reminders that there is a difference between 
the world as theory and the world as fact. One of the 
7 
Stratocumulus. 
healthiest signs of modern day science is the recognition that 
the predictions of science do not invariably occur. The really 
amazing thing is how often present day science is right. 
What we have to say about fogs and clouds here is to list 
their scientific explanation and classification. For a knowl- 
edge of fogs and clouds as fact, observe them yourself. 
