Upper and lower manually operated valves illustrated at 24 and 25, respectively, are illustrated for supplying {HEAD ~ air} through {TAIL ~ the lines} 24a and 25a to the air jet devices 
through
Upper and lower manually operated valves illustrated at 24 and 25 , respectively , are illustrated for supplying { HEAD ~ air } through { TAIL ~ the lines } 24a and 25a to the air jet devices
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH