A substance is anhydrous if it contains no water, for example, salts lacking their water of crystallisation. The way of achieving the anhydrous form differs from one substance to another.
A partial solar eclipse at its peak at 3:37 p.m. in Mesa on Oct. 23, 2014. The eclipse was visible over most of North America and covered 44 percent of the Arizona sun. Michael Chow/The Republic.
The last total solar eclipse within the contiguous 48 United States was on February 26, 1979. Many of those who travelled to see this eclipse were successful but only because of relocating under partly cloudy skies. The total solar eclipse of July 11, 1991 was the last to touch any of the 50 United States.