>the thing I saw Boots do at several Fillmore West shows was, he was back >behind the drum risers and seemed to be venting a explosive gas that rose >upward invisibly in a column and then made a bubble when it hit the ceiling. > After he'd vented some he'd light it and the flame-explosion would climb up >the column of gas & then explode the bubble up under the ceiling.
That sounds more elaborate than what I saw done during the East Coast shows... -Kenny