said plate member and said {HEAD ~ floor} further cooperating to allow {TAIL ~ gas} to seep from said compartment to said chamber for providing a substantially uniform gaseous environment in said chamber 
said plate member and said { HEAD ~ floor } further cooperating to allow { TAIL ~ gas } to seep from said compartment to said chamber for providing a substantially uniform gaseous environment in said chamber
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH