first mounting means disposed on said trap for mounting said trap on {HEAD ~ a vertical wall} of {TAIL ~ said furnace}; and 
of
first mounting means disposed on said trap for mounting said trap on { HEAD ~ a vertical wall } of { TAIL ~ said furnace } ; and
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH