Ralph,

Thanks, I took your suggestion. Wiki produces this: http://upload.wikimedia.org/wikipedia/commons/f/f6/Karte_Helvetik_4.png map which shows that Porrentruy wasn't part of Switzerland in 1802. According to the site on Porrentruy itself, it was incorporated into the department of Haut-Rhin during the Empire. I think I have a map of Haut-Rhin in 1811 so I will go from there. Unfortunately, my creation of maps to illustrate the movements of the Army of Silesia and the second chapter of Weil, has yet another set back.

Again thanks for your help.

v/r Greg