The next day I instanced a rather apt example. Our very knowledge, our mental mastery leads us to false sensory assertions, which become so universal that they develop into apparent truisms. Only by a distinct effort may we summon them to consciousness and correctly orient them. It is not without a wrench that we set aside the evidence of our senses and realize the proof which physics offers. We watch the glorious "sunset" and to disillusion our minds require to repeat again and again that it is the earth which is heaving upward, the horizon which is eclipsing the sun and the sky of day. I once persuaded a group of passengers to speak only of the evening's "earth-rise" and in three or four days this term had become reasonable, and almost lost its strangeness. One finds numerous examples of these sensory deceits at sea; our senses are at fault in every direction. The wind flutters the fins of the flying fish and we think they actually fly. The tropic sea, under the palest of green skies, is saturated ultramarine, save where the propellers churn it to pea-green, yet in our bath the water is clear and colorless. My most interesting oceanic illusion, was a personal one, a result of memory. I looked about the ship and felt that this at least was wholly sincere; it was made to fulfil every function and it achieved its destiny day by day, finally and completely. I had never sailed on a vessel of this name before, the "Yamaro," and yet at certain moments an oblique glance brought a flash of memory, of a familiar hatchway, a rail which fitted snugly under one's elbows, a stretch of open deck which seemed too much of a known path for these few days' acquaintance. As I talked with the Trinidad negro lookout on the forward deck, I saw a brass coolie plate roll out of the galley, and I wondered. There were only negroes among the crew. Then one day I donned my leather waistcoat and climbed down to my anchor flukes, and my mystery was solved. In clear new letters the name of the vessel appeared along the side of the bow above me, but a second glance showed me something else: a palimpsest of old corroded sites of four letters, painted out, which once had sent their message to so many inquiring eyes: Pegu. Long ago, on trips of unalloyed happiness, I had traveled between Colombo and Rangoon on this selfsame steamer, which now, caught in some unusual stress of distant demand of war, had with her sister ships been taken from her route in the Far East and settled to her new routine. So even the ship beneath me was not what she had seemed, and yet her deceit and illusion were harmless, wholly without guile, and I began to wonder whether my unfriendly thoughts of the great city behind me were quite fair.