What is another word for "sky"?

Roget's Thesaurus (1911) lists these synonyms for "sky": aerial, aeriform, aerography, aerology, aerometer, aerometry, aeronaut, aeronautics, aeroscope, aeroscopy, aerosphere, aerostation, affiance, air, airy, analogy, anchor, and, aneroid, anticipation, approximation, aspiration, association, assumed, assumption, assurance, atmosphere, atmospheric, aurora, balm, bare, barometer, baroscope, beam, belief, belle, bit, blue, blush, bottom.