Nahshon was a scholar, producing a dictionary of sorts with explanations of difficult words found in the Talmud. He did not, however, list them in alphabetical order as some others did. Instead, he wrote them down in the order in which they appear, making them more like footnotes.
Looking at the calendar, he realized that there was a cycle of 247 years, after which the order of week days on which any particular festival would fall repeats. He created 14 tables that show this cycle.
There are some writings that are ascribed to him, although we do not know for certain about some of them. One on ritual slaughtering, the Re'umah, is usually said to be his, but authorship cannot be proven. The writings that are believed to be his are often in Aramaic, but some are in Hebrew. His writings do not always agree with prior or subsequent scholars, but he was respected enough in his time to be made head of Sura.
The illustration is a carving of one of the Gaonim teaching at the Sura Academy. Sura and Pumbedita Academies were two chief sources of Talmudic scholarship for centuries, and we will talk about them more tomorrow.