Wow, lots of great information.
The 1901 paper on barrel jump is awesome. Besides being fascinated by the content and the explanation of the effects of barrel harmonics I kept thinking of how they did all the graphing before there were computers
I wonder how long it took the author to create Diagram 11 on page 14 of the PDF by hand.
Thanks for the tip on ladder testing, found this link which has a great step-by-step description http://www.6mmbr.com/laddertest.html