Complex sentence: Melville believed that his party were the only survivors from the "Jeannette"; he knew nothing of De Long's or Chipp's whereabouts.Nevertheless, after resting at Arrhu his group moved on, intending to reach the agreed rendezvous at Bulun.
Split into simpler sentences: Melville believed that his party were the only survivors from the "Jeannette"; he knew nothing of De Long's or Chipp's whereabouts. After resting at Arrhu his group moved on, intending to reach the agreed rendezvous at Bulun.