Their work was like unto the colour of a beryl. — “Work” is used in the sense of workmanship or construction; and “beryl” here, and in Ezekiel 10:9, is not the precious stone of a green colour which we know by that name, but the “chrysolite” of the ancients, the modern topaz, having the lustre of gold, and in harmony with the frequent mention throughout the vision of fire and brilliant light.
A wheel in the middle of a wheel. — We are to conceive of the wheels as double, and one part at right angles to the other, like the equator and a meridian circle upon the globe, so that they could go, without being turned, equally well in any direction. Of course, such a wheel would be impossible of mechanical construction; it is only seen in vision and as a symbol; it was never intended to be actually made.