Bryan:
Thanks for posting all that.
What I'm trying to concentrate on and track the beginnings of is the FIRST appearance of sand bunkering on INLAND courses anywhere where sand was not indigenous as it certainly was on most all linksland and seaside courses.
Once we've established that it would be very interesting to see what it was that was FIRST used on INLAND golf courses in lieu of sand bunkering. For the moment most of the old accounts seem to suggest that most anything already existing that was vaguely hazardous to the playing of shots was used-----eg vegetation (whins, rushes, bushes), walls, roads or apparently even some refuse heaps!
I think the Kellermont account is very interesting as it seems to show the initial problems with using sand in bunkering (it had to be installed on earthen creations that were above ground).
I'd like to track it all back to the very FIRST known example of sand bunkering INLAND (or on the first site where sand was not indigenous and had to be imported for this purpose). As for now Kellermont seems to be remarkably late for that kind of thing INLAND, but perhaps not.
I suppose once we've done all that we could begin to try to determine WHY sand bunkering eventually became almost universally necessary on all golf course architecture everywhere.
At the moment I have a hunch it might've had something to do with that prevalent old knock on courses back then that were not seaside or linksland------eg "Nae links, nae golf."