A=405? I bet that herz...

And don't tell me about the low standards of the French.

Of course, 415 is just a handy number chosen because it is a semitone below modern pitch - there are many instruments made at 409 and even 460 pitches. In the good old days, the makers were only concerned with making instruments in tune with the other instruments they were producing - or, at best, with the pitch used in their area. String players must have been insufferably smug.