When you click on the bottom left, the title of the mapmaker becomes visible. It states : S.Roem. Imp. Principi Johann Friedrich Endersch, Matematicus Regius. S. Roem. Imp. is abbreviation for :Sacrum Romanum Imperium or Holy Roman Empire.
The top right section shows the city of Elbing and the date as MDCCIV.
Outside link to map: [[1]]
Actually, I guess this does tell us a bit about Endersch -- he was Royal Mathematician, and the map was made for the Emperor or his court. It would be a good thing to put that into your stub, rather than just asking everybody to read the Latin... JHK