greener4me suggested there might be helpful information published by Burrard
I don't have Vol. 2 of the 1931 edition, but found data in the 1955 edition, converted to psi, and posted because, unlike Ted, I find it interesting.
There are lots of vintage pressure - distance numbers here, which took some effort to find, and some turn-of-the-century experiments regarding chamber length and "turn over"
https://docs.google.com/document/d/1F2sQuPm05IE4VWYYnCkvuXmYEzQoWd_SQgaAfUOZEFU/edit?tab=t.0

The answer to your question keith is that the numbers are the numbers. If you believe Burrard did sloppy work, please find better numbers and post them.

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