Jan Glete's approximation is for displacement

For his book Navies and Nations, Jan Glete created an approximation so that he could estimate displacements for sailing ships of all nations in the period that he covered from the 16th to the 19th Century. He describes some of that in his book, as quantitative measures were critical to his analysis about the influence of seapower on nation building. He was not working the usual generalities. Instead, he consulted the published literature and used archival sources. In his book, he mentioned the regional archivist Ron van Maanen, who had found information in the Dutch archives beyond what was in the published literature. I have used that information in the past three or four years to make significant progress. At least one other researcher with more direct access to the archives is moving faster than I am.