Vitruvius Quote

There will... be natural propriety in using an eastern light for bedrooms and libraries, a western light in winter for baths and winter apartments, and a northern light for picture galleries and other places in which a steady light is needed; for that quarter of the sky grows neither light nor dark with the course of the sun, but remains steady and unshifting all day long.

Chapter II, Sec. 7 - De architectura (The Ten Books On Architecture) (~ 15BC) - Book I