Constantine I campgate from Constantinople with dot in arch

[Victor]

This one has a dot, high in the archway; perhaps merely operational...an artifact of the engraving process, though it seems oddly placed.

on a side note-- this is a fantastic coin with nicely toned silvering...a current favorite of mine

Constantine I
A.D. 326-327
19mm    3.4g
CONSTAN-TINVS AVG; Laureate head right.
PROVIDEN-TIAE AVGG; camp gate, two turrets, no doors, • in archway, ✶ above; in left field A.
in ex. CONS
RIC VII Constantinople 7 var.

[Lech Stępniewski]

The coin is really great - FDC. But the dot is apparently insignificant.

[Victor]

insignificant maybe...but worth noting...or at least footnoting.

[Heliodromus]

Very nice coin.

The center dot seem to be positioned where expected. Here's an overlayed circle centered on the dot, sized so that the edge is at the center of the on-flan portion of the pearl ring. I think the center dot was basically used to inscribe a layout circle to center the punch marks making up the pearl ring border. The distance between the reverse legend and pearl border (even where off flan) seems about consistent as expected.

I vaguely recall having seen a coin where there were multiple layout circles visible on the coin itself. Not just for the pearl border, but also additional circles (with same center) to help layout the legend. I don't know if this was standard practice or not, but it would make sense. These legend layout circles would have been inscribed very lightly so as to not normally show up on the coin.

In some cases the engraver may have put the circle-center dot/punch to double-duty use by also using it to help layout the design. In case of a partially symmetric design such as the campgate, it would make sense to deliberately engrave the door around the center dot to have it left-right centered within the pearl border.

Ben