15 days now of #LeibnizHomeOffice. Would you like to hear a little something about Early Modern letter-writing and postal systems?

This will be a little less wacky than some of the prior threads - more "nuts and bolts" than just plain nuts. Still, there may be some interesting points from what has been on my desk recently.

Sorry, minor technical problem, but I'm back now. (Actually I'm surprised that we aren't seeing a lot more internet outages and services down at the moment. My home connection was iffy before everyone was stuck at home, and somehow it isn't worse now.)

Still, it's almost appropriate I'm getting an issue precisely now, since hitches in communication systems are one of my topics today. But first, as usual, the little puzzle that got me started on this subject.

A letter from Eckhart to Leibniz begins with a remark (complaint?) that Leibniz's letter of the 22nd of August does not refer to the one Eckhart sent to Leibniz "the previous post-day".

In many ways, this is extremely humdrum. Letters starting with mentions of previous letters, including problems or uncertainties in their transmission, is a very common phenomenon. In a way, it's the equivalent of "Are you there?" and "Can you hear me?" in a teleconference.

For us as editors, it's alternately helpful and frustrating. Bear in mind that we almost never have all the letters in a correspondence. (In this case, we don't have either of the prior letters Eckhart mentions.) Yet we want to reconstruct the sequence of messages.

The mentions in the preserved letters are usually all the evidence we have regarding the missing letters, which may well be more numerous than the preserved ones. And, as always, the letter-writers and recipients know a lot of context that we don't.

Scholarly editions of letters generally develop some standardized form of presenting what information they can extract about the sequence of communication. In the Leibniz correspondence, we have a segment for that at the beginning of our commentary on a letter.

And because, after 100+ years and several generations of editors, everything has a fairly idiosyncratic name, so does this segment. It's internally called "das Zu-Numero", because that's how it always begins. Here's a random example, neither very simple nor exceptionally complex.

Italic K means an autograph letter from one of Leibniz's correspondents. (An autograph letter from Leibniz gets Italic L. Letters written by secretaries get small letters rather than capitals.) So, this letter is a response to a letter we don't have, but whose date is known; ...

... and the answer to it is a letter that we do have, and that appears in that volume as Number 51. The "Zu-Numero" also explains about enclosures, and about anything else we were able to learn about the ways, means or times of communication.

I'm still learning how to write a proper "Zu-Numero". Much of the phrasing is standardized; but all sorts of unusual situations can arise, and I keep having to look up: What was the wording for this when it last occurred? Or is it so rare there isn't a standard wording?

But of course, with Eckhart's letter of 24 August 1708, the immediate problem is this: I needed to convert "the previous post-day" into a calendar date! I had no idea how to do this. So, of course, I asked the old hands.

One of them remembered she once found a list of post-days in a periodical from Leibniz's time. "It hung on my office wall for years..." Unfortunately, it no longer does. And she couldn't remember what periodical.

I asked all the others whether they knew what this source was, or perhaps had a copy of it. No luck. I was preparing myself to scour years' worth of periodicals ...

... but then fortunately someone gave me better advice. There's a reason the list wasn't valuable enough to keep better track of. The usual way to determine post-days is quite simple.

Provided you have enough letters posted from a given location, you simply tabulate the weekdays of their dates. As a rule, one or two days will have most of the dates. These will be the post-days!

So I started with Eckhart, but it didn't work too well. About one-third of the letters were dated from Fridays, but the rest were spread out. Then someone reminded me Leibniz corresponded with several other Helmstedt professors.

Rudolf Christian Wagner was Professor of Mathematics and Physics. He was one of the first to teach experimental physics at Helmstedt; among other things, he would take his students out stargazing at night. (I suspect he was one of the more interesting teachers!)

He was also a protégé and frequent correspondent of Leibniz, heavily involved in the construction of Leibniz's famous calculating machine, which went on for decades. (As I've mentioned, Leibniz wasn't stellar at *finishing* projects.)

As it turns out (as, in fact, the people working on Series III, where his letters are published, already knew), Wagner was also as regular as clockwork in the dates of his letters. Every single one is dated on either a Tuesday or a Friday. Voilà: the Helmstedt post-days!

So, problem solved. Eckhart is writing on August 24 (Friday), complaining that Leibniz's letter of August 22 does not acknowledge receipt of his letter of August 21 (Tuesday). This also tells us something about expected transmission times!

The distances here were short. Leibniz was in Wolfenbüttel at the time. That's about 40 km from Helmstedt as the crow flies; more like 50 km by the major roads the post would have taken, via Brunswick. Expecting things to arrive the same day was reasonable.

Overall, the postal network was fairly dense by this time, and fairly effective. Hanover had 15 regular postal routes at the beginning of the 18th century, most operating twice a week. Some were by carriage, some horseback.

That extract is from an article published by Heinrich Bernhards in 1912 (!). The list keeps getting cited in every new work that comes out about the postal history of the region. Nobody seems to have found anything better...

The importance of a fairly reliable postal network, gradually built up since the 16th century, to the overall development of European society would be difficult to overstate. The "Republic of Letters" was only one of the networks made possible by this.

But that leaves another question. Why are Wagner's letters ALWAYS on Tuesdays and Fridays, and Eckhart's pretty much all over the place? There are several possible answers, all of which may be involved at the same time.

One point, of course, is that Eckhart wasn't always IN Helmstedt. His wife was from Brunswick, and the couple spent a fair amount of time there with the mother-in-law. (Eckhart's in-laws might well be the subject of another thread some day...)

But even if you eliminate the letters that weren't written from Helmstedt, he still doesn't stick to the post-days in his dates. Another possible factor: the post isn't the only way to get a letter from A to B.

There were messengers for hire if you didn't want to wait for the post. Or, if someone you knew was traveling anyway, you might have them carry your letter. This was very common; the post cost money, and everyone complained that things sometimes got lost.

Enclosing letters in other letters was also a frequent practice. You sent one thing only over the long distance, and the first recipient would pass on the enclosed letter. This usually leaves some kind of mention in the letters for us to find.

If more than a letter was being transmitted - for instance, if you were sending some books, or page proofs, or botanical specimens, or whatnot - this became all the more of an issue. Because both the price and the risk of loss went up sharply.

Towards the end of 1708, Eckhart has some books purchased for Leibniz at an auction in Halberstadt. They get shipped by "Bierwagen", beer cart, if I read that letter correctly.

Which fits very neatly with the "Weinschiff", wine boat, once used for a similar purpose by the Austrian monastic scholars I formerly worked on. Wine down there, but of course beer here in the North.

The beer cart will make a nifty "Zu-Numero", but unfortunately it won't be for me to write; that letter will end up in Vol. I,29. Still, you begin to see why there's no end to the possible things for us to write into our Zu-Numeros.

However, I think there's yet another thing involved in explaining Eckhart's dates, and I'll tell you why. It has to do with another little puzzle he gave me. Remember his letter about the students boycotting church services?

It's dated 16 June, which was Saturday, and he says "none of them showed up in church yesterday". I tried hard to find out why they were even expected in church on Friday 15 June. Some local celebration?

But he also mentions the introduction of a new professor into the Faculty as happening "today", and when I looked it up in the minutes of the consistory, I found it happened on Monday 18 June.

So he dated the letter 16 June, but wrote (most of?) it on 18 June. Maybe just a mistake, but it's quite possible he started it one day and finished it another. It's something that probably happened a good deal, only you usually can't tell.

Writing letters by hand was hard work (if you've tried it, you know this) and took a lot of time. Especially if you made first a draft, then a fair copy (which I don't think Eckhart usually did, but Leibniz rather liked to).

People who maintained large networks of correspondents, like Leibniz, spent a very serious percentage of their waking time reading and writing letters. Think you put a lot of hours into e-mails? This isn't a 21st-century novelty.

(I doubt Wagner wrote only on Tuesdays and Fridays; more likely he strictly dated letters the day he posted them, while Eckhart dated the day he wrote or began writing.)

I'm coming to the end of this, although as usual I've only just scratched the topic. The overall point would be: communication technologies and practices have been complex for a long time, not just in the 20th and 21st centuries.

Long before that, there was a constantly shifting mix of media, each with its specific capabilities and costs, variously available or inaccessible to different people. Media interacted with each other, information was transferred between them, people navigated this with skill...

... and because some media were much more permanent than others, the images we can reconstruct today of all this activity are not only very fragmentary, but unevenly so. They skew massively toward the written, though even out of that, the greatest part was ephemeral.

Communications and media history is FASCINATING, it's VERY important to making sense of the history of almost anything else, and although these aren't new realizations anymore, there's a great deal we still don't know. (But not the Helmstedt post-days. We got those.)

So, that's it for today. Hope you weren't expecting anyone to get eaten by rodents; can't do that every time. Tomorrow will be another day, so I'll be off to bed. #StayAtHome if you can, and safe navigating the media tomorrow!