", ▁Wisconsin ▁Natural ▁Resources ▁magazine , ▁October ▁ 1 9 9 9 ▁ ▁Mid west ▁Tre aty ▁Network ▁ ▁Great ▁L akes ▁Indian ▁Fish ▁& ▁Wild life ▁Commission ▁www . gl if w c . org ▁ ▁Category : 1 9 8 7 ▁ri ots ▁Category : O j ib we ▁in ▁the ▁United ▁States ▁Category : Ind igen ous ▁rights ▁protest s ▁Category : Native ▁American ▁history ▁of ▁Wisconsin ▁Category : R i ots ▁and ▁civil ▁dis order ▁in ▁Wisconsin <0x0A> </s> ▁The ▁Nap ier ▁Cub ▁was ▁an ▁unusual ▁and ▁very ▁large ▁experimental ▁▁ 1 6 - cy l inder ▁' X ' ▁pattern ▁liquid - co o led ▁a ero ▁engine ▁built ▁by ▁the ▁British ▁engine ▁company ▁D . ▁Nap ier ▁& ▁Son . ▁The ▁Cub ▁was ▁the ▁only ▁Nap ier ▁' X ' ▁engine ▁design . ▁First ▁flow n ▁on ▁ 1 5 ▁December ▁ 1 9 2 2 ▁in ▁an ▁Av ro ▁Ald ers hot ▁bi plane ▁bom ber ▁aircraft , ▁the ▁only ▁other ▁application ▁was ▁in ▁the ▁Black burn ▁Cub ar oo . ▁Only ▁six ▁engines ▁of ▁this ▁type ▁were ▁ordered ▁and ▁produced . ▁ ▁Design ▁The ▁four ▁banks ▁of ▁four ▁cyl ind ers ▁were ▁arranged ▁in ▁a ▁fl atten ed ▁' X ' ▁when ▁viewed ▁from ▁the ▁front . ▁The ▁angle ▁between ▁the ▁upper ▁cyl ind ers ▁was ▁ 5 2 . 5 ▁degrees , ▁the ▁lower ▁cyl ind ers ▁ 1 2 7 . 5 ▁degrees , ▁which ▁gave ▁an ▁angle ▁of ▁ 9 0 ▁degrees