This is the definition of the "Firmament"and the "Raqiya"as taken from the King James Version - which I despise with all of my heart and soul. I went in the KJV and dug out the definition for all of you so you could see it taken from your bible. 

Now I've leveled the playing field and you have zero reason not to believe it. 

the KING JAMES VERSION clearly states that it means - properly an expanse, the is, the Firmament or (Apparently) visible arch of the sky: - Firmament.

It shows up in the KJV 17 times. 

there should be no confusion there is now, there is none. The firmament is the perception of a curvature to the sky - the very very flat sky.