Nice find, but how do you know that this was the only meeting that Hitler attended that day? Your reference says that the meeting lasted only 2 hours, then lunch, with all guests leaving by about 4 pm. Google maps gives the shortest driving route between Berlin and Cologne as 579 km, 5 hr:21m. That's 359 miles; eyeballing it, about 66 mph.
Don't know about the roads and speed limits back then, but if an airplane was available, I suppose the trip back might have only taken about 1 1/2 hours. Still lots of time for a meeting.... even if not during banker's hours.![]()
You're strateching a little there.
The first autobahn wasn't opened until 1935...