“Today, we have meatloaf with mashed potatoes and peas“ – Finding the Really Important Among 1000+ Unknown Letters
Some years ago, I visited the “Bibelhaus,“ a museum about the culture and environment of the Bible, in Frankfurt and took part in a guided tour. The guide showed us a ball of papyrus to show us the material on which biblical texts were written. One question immediately hit me and I asked him: “What if we had an original biblical manuscript in our hands? Why don’t you unwrap it?” He replied that if we were to read “5 goats, grain, etc.” from the outside, everything would look like a shopping list or an invoice. We wouldn’t bother. Reading ‘Jesus said’ would be more interesting.
When I started my doctoral thesis, I first had to sort over 1000 letters from the 19th century with almost 4000 pages of text, which were all addressed to Heinrich Bassermann. Nobody had held those for almost 110 years and no one knew their content. I was interested in biographical information, but at first, I had to solve the great difficulty of deciphering the more than 200 different handwritings. Quickly, I was able to read the sender data and locations very well, which I then listed in an Excel spreadsheet. At some point, I noticed that there were certain days in the year when Bassermann received a particularly large number of letters. For example, one sender always sent him a letter every year on July 11th – the day before Bassermann’s birthday.
In order to make such regularities visible, I had the idea to list the letters in a crosstab. Around the birthday, for example, I got the following result:
This result does not look spectacular at first glance, yet the many ‘0’ give the impression that something cannot be right in my approach. On the one hand, this is only an excerpt of 11 letters (<1%). On the other hand, two little things become visible on closer inspection: First, 1899 was Bassermann’s 50th birthday, which means that he got more mail. Second, apparently in the 19th century, congratulations were not given retrospectively.
The matter becomes more informative if one looks at the entire crosstab. However, it consists of 44 rows (header + 43 years from 1867-1909) and 367 columns (index + 365 days + leap day), i.e. 16148 cells. This is not easy to overview. That’s why I colored the table and created a heatmap like this:
Each small horizontal line in this map represents one day separated by year. The color (I used grayscales because of the print version) indicates the number of letters that arrived on that day. I have already marked some conspicuities with the grey frames – the wide horizontal frame in July frames the birthday and you can see very clearly that his 50th was in 1899.
At first, I noticed the thick deep grey line in September 1879. I already knew that Bassermann’s firstborn daughter died of a childhood disease at the age of 4 on September 24th, 1879. It is no surprise that in the 19th century life events coincide with correspondences. Therefore, it did not surprise me to find only condolence letters in the corpus around this date. Then, I looked at other dates with dark grey bars and periods where the lines are close together. In October 1878, many letters came because Bassermann was planning to publish a new journal. In March/April 1896, friends and colleagues congratulated him on becoming vice-rector of the University of Heidelberg.
In fact, this heatmap has helped me a little to identify periods and days when something happened that might be relevant to a biography. This saved me a lot of time and I didn’t have to struggle through 4000 handwritten pages. And it proved that correspondences correspond with great life events. Surely, I don’t have the guarantee that not the one single letter at the beginning of January 1908 is not enormously important. But such a representation of a completely unknown corpus of letters can help to prioritize. Finally, don’t worry: I also found out that Bassermann liked meatloaf and wrote shopping lists.