Ezekiel 1:15 - Clarke's commentary and critical notes on the Bible

Now as I beheld the living creatures, behold one wheel upon the earth by the living creatures, with his four faces. One wheel upon the earth - It seems at first view there were four wheels, one for each of the living creatures; that is, the creatures were compound, so were the wheels, for there was "a wheel in the middle of a wheel." And it is generally supposed that these wheels cut each other at right angles up and down: and this is the manner in which they are generally represented; but most probably the wheel within means merely the nave in which the spokes are inserted, in reference to the ring, rim, or periphery, where these spokes terminate from the center or nave. I do think this is what is meant by the wheel within a wheel; and I am the more inclined to this opinion, by some fine Chinese drawings now before me, where their deities are represented as walking upon wheels, the wheels themselves encompassed with fire. The wheel is simply by itself having a projecting axis; so of these it is said, "their appearance and their work was, as it were, a wheel within a wheel." There were either two peripheries or rims with their spokes, or the nave answered for the wheel within. I have examined models of what are called Ezekiel's wheels, which are designed to move equally in all directions: but I plainly saw that this was impossible; nor can any kind of complex wheel move in this way.