There is a problem for this analysis based on lines of latitude because Rome is nearly on the same latitude as Apsaros, which is one of the outposts of the Empire. Rome is a large city and its center is about eighteen miles north of Apsaros, which was a fortress on the east shore of the Black Sea (Pontus Euxinus). In the chart below this nearness of latitude is demonstrated by the pink and overlapping green line extending from the lower right corner upward to just below the right corner. Apsaros is at 41.6° and Rome at 41.9. The physical distance between the latitude lines is about eighteen miles, and their point three degrees separation on the picture is quite small, as is demonstrated by the closeness of the two lines even after being projected corner to corner on the picture seen below.
Even with this closeness of angle the lines projected for Rome were clearly different in their creation of hot spot intersections with the projected lines coming from the sundial at the top of the picture. The hot spots are created by an overlap of a minimum of three separate lines, with at least two coming from a separate set of three aligned important points such as sages’ eyes or toes etc.. The green circles are hot spots for Rome and they have their lines of latitude shown going from important points to at least two other important points. The Apsaros lines have been omitted because this is a demonstration of Rome’s lines, but the Apsaros hot spots were created using the same criteria as Rome’s and have been shown with their color-coded pink circles.
It was a surprise to me how very different the two sets of hot spot circles were because I had located these two sets of lines and their associated circles without reference to the other. One would think that with the lines being so very close together in their angles there would be similar hot spot hits, but you may observe they are totally different.
Whoever created the Seven Sages of Greece mosaic had their latitude lines accurate to a minimum of a tenth of a degree.