That day, too, ended with the work of trimming the wick of the kerosene lamp to an even length. The flame grew to the length of a fingertip and sank again, and above it the revolving lens, wound on its brass clockwork, turned slowly. The light swept the black sea once at regular intervals — once every twelve seconds, always from the same place. Below the tower the island's tidal rocks lay drowned in darkness, and beyond them I could not judge how far the surface of the water reached. I stood with my hand on the rail of the lantern gallery, counting the monotonous arc the light cut as it turned away. There was a kind of solace in the counting. Five months since I had landed on the island; I no longer remembered when I had last shaped a human word with my mouth.
The only thing that broke that monotony was the sound of water rising from beneath my feet. The flood tide came over the flats at its appointed hour and withdrew at its appointed hour. The sea did not break its promise — the West Sea tides, at least, did not. At the spring tide it climbed far in; at the neap it bared the black backs of the tidal rocks. Listening to that coming and going, I came to admit that the regularity of this water was the one companion the uninhabited island offered.
Among a keeper's duties is the recording of the tide each watch. There was a printed tide table sent down by the Bureau, and beside it I set down the water's true height to compare. The table was nailed to the inner wall of the tower; it had hung there before my posting, left by my predecessor. Who he was I do not know. The handover had been finished on the mainland with a single sheet of paper, and all he left behind was that table and a pair of scissors worn into the habit of cutting wicks too short.
That night, when I brought the lamp to the table to check the tide of the coming watch, I saw a single line written by hand among the printed columns.
It was not type. At the very bottom of the table, in the margin that should have been blank, someone had drawn in an extra cell with ink and entered a time. It was some hour between midnight and dawn — but that day was the dark of the moon, and on a moonless night no such tide could come. Neither spring nor neap, a tide on no table at all. In the margin beside it, in small letters, a single phrase was written.
"The thirteenth tide."
The instant my fingertip traced those letters, a cold like ice ran down my spine. "The tower in September is cold like this as a matter of course," I muttered to myself, trying to give a reasonable account of the chill that seemed to pour from the nailed table. It was not that the table was cold because it hung there — only that the table had been hung in a place already cold, I added.
My predecessor was a man who cut his wicks too short. He would have been idle enough, too, to write a joke into a tide table. The nights on an uninhabited island are long, and when they are long a man will write down anything at all.The lamp had been made in Glasgow and had reached this island by way of the Qing. On the brass mount that held the lens the maker's plate was engraved, and in five months I had only polished it, never read it. That day, when I brought the lamp close, a single line of Latin engraved on the mount rose to my eye.
LUMEN SUPER ABYSSUM CUSTODIT"It keeps the light above the abyss" — as a lighthouse's motto it was a fitting sentence. But whether the light kept the abyss from something, or kept the light from the abyss, the Latin did not say.
I resolved to wait out the hour written in the table. Out of fidelity to my duty, I told myself. To confirm that a tide on no table would not come, and so to strike a line through my predecessor's scribble.
Past midnight, at the low-water hour of the printed table, the water withdrew exactly. The flats lay bared, black, to the very edge of the lamplight. I set the height down in the logbook. The promise was kept.
And when the hour written by hand arrived, the water withdrew once more.
The sentence breaks off there. I took up the pen to write the next letter, but at my fingertip something refused the pen. It was the same kind of cold as when I had touched the nailed table. Yet the ink went on. Without my being aware of it, the letters were set down — slowly, for those who come after.
██ ████ █ ███████.In that instant the clockwork of the slowly turning lamp faltered once — for a very brief moment. That was all, and presently the light went on cutting its twelve-second arc again. There was no wind. The flats still lay withdrawn to a depth no printed table would allow.
I set the time down precisely in the margin of the logbook. Surely an old gear had slipped once — five months turning without rest; even clockwork might catch its breath one time, might it not?
Even now, as I write this, the lamp turns at my back. Beside the Latin of the brass mount, the light sweeps the black water once every twelve seconds.
I look at the familiar grain of the mount. Will it not falter once more — but the clockwork does not stop.