In the UK , numbers of winning Premium Bonds ( which were not strictly a lottery , but very similar in approach ) were generated by an electronic machine called ERNIE.ng arms inside ; the drum itself may or may not rotate .
In the UK , numbers of winning Premium Bonds ( which were not strictly a lottery , but very similar in approach ) were generated by an electronic machine called ERNIE . 
 A '' gravity pick machine '' has a drum with rotating arms inside ; the drum itself may or may not rotate .