said vapor removal means comprises a vapor collection region extending along {HEAD ~ the top} of said tank from one chamber to the other, vapor outlet means from said region, and said zones opening inwardly to {TAIL ~ said region}, 
said vapor removal means comprises a vapor collection region extending along { HEAD ~ the top } of said tank from one chamber to the other , vapor outlet means from said region , and said zones opening inwardly to { TAIL ~ said region } ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH