another of the early earendel poems , 'the shores of faery ' , has a short prose preface , which if not as old as the first composition of the poem itself ( july 19i5 , see p. 271 ) is certainly not much later : earendel the wanderer who beat about the oceans of the world in his white ship wingelot sat long while in his old age upon the isle of seabirds in the northern waters ere he set forth upon a last voyage .