23 DEEP WELL WATER PUMPING AND WATER SUPPLY SYSTEMS AND APPARATUS OF THE TYPE WHEREIN WATER IS PLACED UNDER PRESSURE BYA MAIN PUMPING MEANS SUCH AS A CENTRIFUGAL PUMP AND IS PIPED DOWN WARDLY ALONG A MAIN SUCTION PIPE AND IS DISCHARGED UPWARDLY WITHIN THE MAIN SUCTION PIPE THROUGH AN INJECTOR NOZZLE STRUCTURE TO INCREASE THE OPERATING EFFICIENCY OF THE SYSTEM, AND PARTS THEREOF