half past seven
Percy 's experience with automobiles stood him in good stead . He was naturally interested in machinery , and soon mastered the details of the _ Barracouta 's _ engine . The others also showed themselves apt pupils . At half past seven the high cliffs of Seal Island lay to the north . Passing for a mile along its rocky shores , they kept on toward Matinicus , now rising into view . Jim pointed to a breaker a little south of their course . `` Malcolm 's Ledges !