Marvin C. Howe and Stopped Horn

Marvin C. Howe once wrote:

"It has long been the custom and the practice to assume that stopping the French horn in F raises the pitch a minor second (1/2 step).  This apparent change is corrected by fingering the stopped passage 1/2 step lower than written.  As far as fingerings are concerned, an F part (stopped) is fingered as though written for Horn in E; an E part is regarded as being in E flat, etc.

It is not the intention to negate the practicality of the above assumptions, for the fingerings obtained are certainly workable.  However, it will be shown that the above assumptions are false.  In fact, the hand always lowers the pitch--albeit unevenly--to a new pitch one half step above the next lower member of the harmonic series being employed.  This does result in a series one half step above those obtained when playing "open" horn, but the new pitches are (and always were!) derived from above.  Practice of this derivation results in better and quicker control of stopped horn than is generally obtained by the horn student."

Can anyone explain this better?  I become lost in the second to last sentence.  Does anyone know of a better explanation?  I met Marvin Howe at Interlochen in the last years of his life.  My teacher at the time, Dr. Randall Faust, introduced us.  I was fortunate that we were able to play horn quartets together in front of Corson Auditorium by the bronze sculpture of "The Bears".  He was a trooper.  I remember it was a hot day.  I think it was the only time I played quartets with someone who was on an oxygen tank.  He played fine as I recall.    

Back to stopped horn.  James Decker had come up with a fingering chart for B-flat horn fingerings and stopped horn.  They worked wonderfully in terms of accuracy and intonation but I never got a copy of them during my days at USC when I was also known as "Merv" Griffin. Since then, I fudge around and find ones that work on the B-flat horn. I have recently started using B-flat fingerings for middle C and below and it's been working great!  Anyhow, since have have been teaching students of my own, I've been at a loss for words in explaining the exact acoustical science behind what actually happens when we stop the horn.  I find myself saying "suffice it to say" too often and that's just not good enough for me.