‘Now as I beheld the living creatures, behold one wheel upon earth beside the living creatures, for each of their four faces. The appearance of the wheels and their work was like the colour of topaz, and they four had one likeness, and their appearance and their work was as it were a wheel within a wheel. When they went they went to their four sides. They did not turn when they went.'
By each living creature was a wheel, each similar to the other, yet not like an earthly wheel, although it rode upon the earth, for seemingly the wheels went all ways. We cannot be fully sure what the description meant, but the principle is clear. They were splendid, like gleaming yellow topaz or chrysolite, they rolled over the earth bearing the platform on which was God's throne, they could go all ways, and they went forward without turning to one side or the other. It was the divine chariot of God. There may be some connection with whirlwinds for in chapter 10 they are called ‘the whirlers', possibly likening them to whirlwinds.
Note the continued emphasis on the fact that its path never deviated. As Ezekiel watched, it came inevitably and inexorably on. Nothing could stop it.