If we use deduction then we can look at the simple fact that Earth is a globe, and conclude that the meaning of the word circle in Isaiah 40:22 is sphere. In this case the Hebrew word translated as circle also means sphere.
One of the most well known events in the science vs. faith fiasco was a match up between Ken Ham and Bill Nye. The debate between was on the question "Is Creation A Viable Model of Origins?"
The third heaven is the dome or firmament, which is a sea of glass. It's a rigid crystalline sphere on the edge of space which formed in response to the creation of gravity on the second day.
Circle, sphere: ח֣וּג - chug * to draw a circle, to circumscribe, Job 26:10. * masc. circle, sphere, * fem. compass, compasses, Is 44:13.
Accepting the firmament as a sphere of rigid crystal on the edge of space solves many scriptural and physical problems. The King James Version is the only Bible from which an accurate cosmological model may be deduced.
Sing unto God, sing praises to his name: extol him that rideth upon the heavens by his name JAH, and rejoice before him.
And before the throne there was a sea of glass like unto crystal: and in the midst of the throne, and round about the throne, were four beasts full of eyes before and behind.
And I saw as it were a sea of glass mingled with fire: and them that had gotten the victory over the beast, and over his image, and over his mark, and over the number of his name, stand on the sea of glass, having the harps of God.
It would appear that "the foundations of heaven" and "the foundations of the wall of the city" are the same thing. Are the firmament and the foundations of heaven the same thing?
One of our favorite ways to study the Bible is to follow a doctrine through from the first time it's mentioned to the last. This is a great way to develop understanding of the doctrine in the broad narrative of scripture.