Nowadays the so-called Monogram of Christ is almost always reproduced for us as

or

; but the fact that Constantine sometimes so used it should not blind us to the facts that it was at first usually the centre of a circle, like the spokes of a wheel; and that the undisguised solar wheel

appears upon not a few of the coins issued by the Christian successors of Constantine, while since his reign the solar wheel

and many an artistic variation of the same have been Christian symbols, and when in our ornamentation of ecclesiastical properties we omit the circle we as often as not make the cross itself wheel-like by rounding the extremities and widening them till they nearly meet.

Moreover it should not be forgotten that it