Sexta Europe. Tabula.

Identifying and dating maps from the Rome edition

As noted, four distinct editions of the Rome Cosmographia were issued, but the bulk of the maps was printed from the same plates as the original 1478 edition. Consequently, it can be difficult, if not impossible, to identify from which edition a loose map might derive. We might as well state it outright: there is no way to know from which edition of the Rome Cosmographia our particular map comes.

Two principal clues aid scholars in dating separated Rome Ptolemy maps. The first, as mentioned above, are minor variations in the maps from edition to edition. Unfortunately, Prima Asiae Tabula has no variations in the four Rome editions. The second clue involves the paper’s watermark. Marcel Destombes (1952) was the first to seriously argue that individual sheets of the Rome editions could be identified by their watermark. Destombes also provided some initial analysis by attributing certain watermarks to specific editions, including a claim that a crossbow and lion denoted the 1478 edition. In contrast, a cardinal’s hat, a ladder, a French lily, or a T in a circle represented the 1490 edition.

More recent scholarship (Peerlings et al. 2017) has reinforced the idea that specific watermarks can be associated with certain editions. Still, they also note how – due in part to the printing procedure – many map sheets do not allow dating in this manner – at least not with any degree of certainty. Some maps, for example, have two contradicting watermarks, one in each half. In other cases, there is no watermark; this is the case for our map, which lacks a watermark.

Why would most Rome Ptolemy maps have one or two watermarks while others have none? We find the answer to this question in the printing methodology. Roughly half of the loose maps have two watermarks, whereas about a quarter have one, and about a quarter have none. Mathematically, this is explained by the procedure by which such maps were printed. We have already noted how these maps were printed as two halves and joined, with no text on the verso. In all likelihood, the reams of paper for printing would have required that each sheet was cut in half and subsequently printed using a single copperplate (i.e. half of a map). The printer completed each run before moving on to the next, seemingly indifferent to what sheet halves were used.

The consequence was a random mixture. Each large sheet of paper had one watermark but would become two sheets for printing. Later, the two halves were joined again to form the final map. If the printer did not concern himself with what half of a sheet was being used, or indeed what face or direction the paper turned when printing, statistically, the outcome would reflect what we have today. The procedure not only explains why we have sheets with no watermarks but also why there are sheets that have two. It even explains those rare cases where the two halves of a map contain different watermarks. Because the same plates were used in all four editions, half-sheets from different editions may have been joined in later composite atlases or simply from old inventory.

Skelton has argued that about 500 copies of the original 1478 edition were published, marking the smallest run of the four editions. Moreover, the variation of watermarks in the 1478 edition is the most limited, making their attribution easier as long as a watermark exists. In the case of no watermark, raw statistics suggest that 1478 is the least likely date for an unmarked map. However, even when no watermark exists, secondary indications can help one hone in on the date. The most critical element in this regard, which several scholars have noted, is that the 1478 and 1490 editions were printed on high-quality paper, which is certainly true of our map.

In light of the complex history behind this seminal work, Neatline cannot guarantee from which edition of the Rome Cosmographia our sheet derives. What we can say, however, is that it was printed from Sweynheym’s original plate without variations or amendments and that it belonged to one of the most important geographic publications in history.