nach "course of the sun" = Sonnenlauf

... would be my approach.

This makes the most sense to me, as an amateur historian of Renaissance astronomy. You could also say "location," which would mean the same thing in 17th-century terms, but "motion" is closer to "lauf."

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Note added at 37 mins (2009-09-22 12:06:45 GMT)
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Actually, unless this is a translation of a rigorous treatment of the history of science, it doesn't matter which of these various options you choose, since very few almanacs exist from that period in English, and the point in any case would be to be clear to a modern reader. Whatever they called it in German, there would be no standard translation in English, I don't think. (Scientists wrote in Latin mostly anyhow.) If it's an academic treatment, however, you would want to get it just right, which would mean looking at some actual almanacs from 17th century England.