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Make Your Own Cyanometer: A Tool for Blue Sky Thinking
Have you ever looked at the sky and wondered just what that shade of blue is? A cyanometer is an instrument that lets you measure the blue of the sky. It was invented in 1789 by Swiss physicist Horace-Bénédict de Saussure. He created it from 53 squares of paper dyed with Prussian Blue, ranging from… read more
