“How many miles to Babylon?”

The answer to this famous nursery rhyme – “three score and ten”, i.e. 70 km – seems outrageously high for a day's journey, no matter “if your heels are [exceptionally] nimble and light”. (Even swift-footed Achilles would struggle to cover 70 km in day!) So, what are we to make of it? How can we evaluate such a distance number?

This is where the "database ancient measurements" comes in. The project was initially sponsored by Berlin's excellence cluster TOPOI and is managed now by my IT whiz Rainer Streng who set it up in MS Access and programmed data exports into "Google Earth" and applications in "ArcGIS 10". Irina Tupikova, who by day is an astronomer and mathematician, is also working on Ptolemy's data, recalculating the spherical coordinates to the original measurements.

As far as we know, there is no comparable collection of this kind. Right now, our database includes nearly 100 ancient authors and their works, especially ancient geographers and historians (Strabo, Pliny, Hero­do­tus, Thucydides etc.), but also minor authors like the pseudo-Aristotelian work de mundo or Horace's Satires. All in all we have in our database 2466 "distances", i.e., attested routes with two points and a number. (Among them eleven routes for Babylon, and even bigger figures for a "day´s journey" than the 70 km in the nursery rhyme, if you are interested!)

What can one do with these data? We think: a lot! To start with:

• How accurate and reliable were ancient measurements data?
• What units are attested and how do they relate to each other? This is a basic and notorious question in the field of ancient metrology.
• Who measured or rather estimated distances in antiquity? Soldiers, explorers, merchants? Were there any attempts to map a whole country or empire and standardize the many distances in antiquity? If so, was this a "bottom-up" process done by practitioners like seamen or merchants or a "top-down" one, organized by a central administration?

But there are potentially much more searching questions, such as:

• How does an ancient author employ numbers, especially distances as a means to engage with his readership, in order to bring home his own ideas or concepts? Authors like Herodotus or Thucydides were very careful (and sometimes even deceptive!) in using numbers in their narratives.
• How can we use measurement data to explore one of the most basic, important and comparable properties of space is its extension, its spatiality? If researchers concern themselves with spaces, they should not ignore this aspect (as they mostly do). Distances are a means to evaluate the different concepts of space the ancients had in mind. But they allow us also to reconstruct not only the real maps of ancient geographers but also the "mental maps" of merchants, soldiers, intellectuals etc.
• How can a corpus of ancient measurement data allow us to reconstruct ancient routes and waterways and, in addition, social phenomena like migration or mobility? The ambitious application Rainer works on now, is an ancient network of ancient routes and waterways (something like Orbis or Omnes Viae, but based on our measurement data).

To give just a small example:

The green line depicts the route between Tridentum and Rome, a route, which according
to the "codex Theodosianus" (6.28.1) can be covered in 34 days. 34 days of travel
are "normally" equivalent to c. 850 km (a day´s journey calculated as 25 km). The
linear distance according to Google Earth is 477.58 km. But our ArcGIS model shows that
the route on known Roman roads is in fact 90 km lon­ger, i.e. 567.40 km.

The meetings with the nimble-footed Pelagios team (zigzagging between several locations all over Berlin in one and a half days) helped us sharpen our own profile and scientific approach tremendously. Fine-tuning our data and making it compatible and interoperable with the other Pelagios partners will be undertaken over the upcoming months. Watch this space!