Big John wrote
1. A 'barrel roll' is a roll where (if done properly) you as a
passenger, with your eyes closed, can not tell you did a roll.
The ball stays centered and if one 'G' is maintained, it feels
like straight and level flight. Starting nose position and of
course air speed varies between underpoweed GA aircraft and
super sonic Fghters.
There are also a few fine points the experts use that I have not
covered but above are the basics.

Been there done that for longer (65 years) than BOb has been
flying. )

I have e-mailed BigJohn and posted at:

alt.binaries.pictures.aviation

a scan from William Kershner's book, The Flight Instructor's
Manual, in which he describes the barrel roll as an acrobatic
maneuver. You probably know that Mr. Kershner is one of the most
respected names in the flight training field, having authored
several books on the subject. Not as funny as Machado, but he has
been around for a much longer period of time.
I haven't scanned and OCRed the text because I think that the
picture is self-explanitory, but if it would help, I will do the
page of text describing the barrel roll.

Note that as mentioned in my previous post quoting from:

http://acro.harvard.edu

that one cannot maintain "one G" in a barrel roll since it involves
both a loop and a roll. In order to perform the loop portion, one
must pull at least 3-3.5 Gs in the pull-up and a similiar force in
the pull-out. While inverted, the g-force drops to .5-1 g as in a
normal loop.

I readily conceed that Big John as been around a bit longer than I,
but by the the time that I flew in the military, we were learning
to fly in "airplanes", not "birds". :-) :-)

Bob