The so-called "Monogram of Christ" can be seen, for instance, upon a monument of Isis, the Virgin Mother of the Sun-God, which dates from the second century before our era.[51] Also upon the coins of Ptolemaeus; on one of which is a head of Zeus Ammon upon one side, and an eagle bearing the {image "monogram3.gif"} in its claws upon the other.[52] The symbol in question also appears upon Greek money struck long before the birth of Jesus; for instance upon certain varieties of the Attic tetradrachma. And the {image "monogram4.gif"} occurs upon many different coins of the first Herod, struck thirty years or more B.C. Whether the Pagan {image "monogram3.gif"} and the Pagan {image "monogram4.gif"} originally had the same signification or not, is uncertain. Almost equally uncertain is the date at which we Christians first adopted these Pagan symbols as Christian symbols because they could be interpreted as formed of the two first letters of the Greek word XPI{sigma}TO{sigma}, _Christos_, Christ. The probability is that Christians had at least drawn attention to this possible interpretation of the symbols in question before the days of Constantine. But this scarcely renders less noteworthy the fact, shown further on, that the favourite symbol of the Gaulish warriors, the solar wheel {image "solarwheel1.gif"} or {image "solarwheel2.gif"}, was sooner or later altered by their leader into {image "monogram1.gif"} or {image "monogram2.gif"} to please the Christians; while the symbols {image "monogram3.gif"} and {image "monogram4.gif"} were also made use of by Constantine. Which form of solar wheel, monogram, or cross, was that actually carried by the Gauls in triumph within the walls of Rome and set up by their leader in the heart of the Eternal City, is not quite certain. But it is clear that as both the {image "monogram3.gif"} and the {image "monogram4.gif"} appeared upon coins struck before our era, Constantine cannot very well have been ignorant of the fact that these were originally Pagan symbols, when he favoured the addition of a loop to the top of the vertical bar of the Gaulish solar symbols {image "solarwheel1.gif"} or {image "asterisk.gif"} and {image "solarwheel2.gif"} or {image "plus.gif"} in order that what his Gaulish army venerated as triumphal tokens might be accepted as symbols of victory by his Christian supporters also. That this Gaulish monarch did so alter, and for the reason named, the symbol or symbols venerated by his troops, is admitted by, amongst others, that well known writer the Reverend S. Baring Gould, M.A. For, referring to the solar wheel as a symbol of the Sun-God venerated by the ancient Gauls, this author tells us that Constantine