The Cruise of the Snark, Jack London [top 50 books to read .TXT] 📗

was in northern declination and nearly overhead. The legitimate "chronometer-sight" method of ascertaining the longitude I had not heard of--yes, I had heard of it. My first captain mentioned it vaguely, but after one or two attempts at practice of it he mentioned it no more.

I had time in the Fijis to compare my chronometer with two other chronometers. Two weeks previous, at Pago Pago, in Samoa, I had asked my captain to compare our chronometer with the chronometers on the American cruiser, the Annapolis. This he told me he had done-- of course he had done nothing of the sort; and he told me that the difference he had ascertained was only a small fraction of a second. He told it to me with finely simulated joy and with words of praise for my splendid time-keeper. I repeat it now, with words of praise for his splendid and unblushing unveracity. For behold, fourteen days later, in Suva, I compared the chronometer with the one on the Atua, an Australian steamer, and found that mine was thirty-one seconds fast. Now thirty-one seconds of time, converted into arc, equals seven and one-quarter miles. That is to say, if I were sailing west, in the night-time, and my position, according to my dead reckoning from my afternoon chronometer sight, was shown to be seven miles off the land, why, at that very moment I would be crashing on the reef. Next I compared my chronometer with Captain Wooley's. Captain Wooley, the harbourmaster, gives the time to Suva, firing a gun signal at twelve, noon, three times a week. According to his chronometer mine was fifty-nine seconds fast, which is to say, that, sailing west, I should be crashing on the reef when I thought I was fifteen miles off from it.

I compromised by subtracting thirty-one seconds from the total of my chronometer's losing error, and sailed away for Tanna, in the New Hebrides, resolved, when nosing around the land on dark nights, to bear in mind the other seven miles I might be out according to Captain Wooley's instrument. Tanna lay some six hundred miles west- southwest from the Fijis, and it was my belief that while covering that distance I could quite easily knock into my head sufficient navigation to get me there. Well, I got there, but listen first to my troubles. Navigation IS easy, I shall always contend that; but when a man is taking three gasolene engines and a wife around the world and is writing hard every day to keep the engines supplied with gasolene and the wife with pearls and volcanoes, he hasn't much time left in which to study navigation. Also, it is bound to be easier to study said science ashore, where latitude and longitude are unchanging, in a house whose position never alters, than it is to study navigation on a boat that is rushing along day and night toward land that one is trying to find and which he is liable to find disastrously at a moment when he least expects it.

To begin with, there are the compasses and the setting of the courses. We sailed from Suva on Saturday afternoon, June 6, 1908, and it took us till after dark to run the narrow, reef-ridden passage between the islands of Viti Levu and Mbengha. The open ocean lay before me. There was nothing in the way with the exception of Vatu Leile, a miserable little island that persisted in poking up through the sea some twenty miles to the west-southwest-- just where I wanted to go. Of course, it seemed quite simple to avoid it by steering a course that would pass it eight or ten miles to the north. It was a black night, and we were running before the wind. The man at the wheel must be told what direction to steer in order to miss Vatu Leile. But what direction? I turned me to the navigation books. "True Course" I lighted upon. The very thing! What I wanted was the true course. I read eagerly on:

"The True Course is the angle made with the meridian by a straight line on the chart drawn to connect the ship's position with the place bound to."

Just what I wanted. The Snark's position was at the western entrance of the passage between Viti Levu and Mbengha. The immediate place she was bound to was a place on the chart ten miles north of Vatu Leile. I pricked that place off on the chart with my dividers, and with my parallel rulers found that west-by-south was the true course. I had but to give it to the man at the wheel and the Snark would win her way to the safety of the open sea.

But alas and alack and lucky for me, I read on. I discovered that the compass, that trusty, everlasting friend of the mariner, was not given to pointing north. It varied. Sometimes it pointed east of north, sometimes west of north, and on occasion it even turned tail on north and pointed south. The variation at the particular spot on the globe occupied by the Snark was 9 degrees 40 minutes easterly. Well, that had to be taken in to account before I gave the steering course to the man at the wheel. I read:

"The Correct Magnetic Course is derived from the True Course by applying to it the variation."

Therefore, I reasoned, if the compass points 9 degrees 40 minutes eastward of north, and I wanted to sail due north, I should have to steer 9 degrees 40 minutes westward of the north indicated by the compass and which was not north at all. So I added 9 degrees 40 minutes to the left of my west-by-south course, thus getting my correct Magnetic Course, and was ready once more to run to open sea.

Again alas and alack! The Correct Magnetic Course was not the Compass Course. There was another sly little devil lying in wait to trip me up and land me smashing on the reefs of Vatu Leile. This little devil went by the name of Deviation. I read:

"The Compass Course is the course to steer, and is derived from the Correct Magnetic Course by applying to it the Deviation."

Now Deviation is the variation in the needle caused by the distribution of iron on board of ship. This purely local variation I derived from the deviation card of my standard compass and then applied to the Correct Magnetic Course. The result was the Compass Course. And yet, not yet. My standard compass was amidships on the companionway. My steering compass was aft, in the cockpit, near the wheel. When the steering compass pointed west-by-south three- quarters-south (the steering course), the standard compass pointed west-one-half-north, which was certainly not the steering course. I kept the Snark up till she was heading west-by-south-three-quarters- south on the standard compass, which gave, on the steering compass, south-west-by-west.

The foregoing operations constitute the simple little matter of setting a course. And the worst of it is that one must perform every step correctly or else he will hear "Breakers ahead!" some pleasant night, a nice sea-bath, and be given the delightful diversion of fighting his way to the shore through a horde of man- eating sharks.

Just as the compass is tricky and strives to fool the mariner by pointing in all directions except north, so does that guide post of the sky, the sun, persist in not being where it ought to be at a given time. This carelessness of the sun is the cause of more trouble--at least it caused trouble for me. To find out where one is on the earth's surface, he must know, at precisely the same time, where the sun is in the heavens. That is to say, the sun, which is the timekeeper for men, doesn't run on time. When I discovered this, I fell into deep gloom and all the Cosmos was filled with doubt. Immutable laws, such as gravitation and the conservation of energy, became wobbly, and I was prepared to witness their violation at any moment and to remain unastonished. For see, if the compass lied and the sun did not keep its engagements, why should not objects lose their mutual attraction and why should not a few bushel baskets of force be annihilated? Even perpetual motion became possible, and I was in a frame of mind prone to purchase Keeley- Motor stock from the first enterprising agent that landed on the Snark's deck. And when I discovered that the earth really rotated on its axis 366 times a year, while there were only 365 sunrises and sunsets, I was ready to doubt my own identity.

This is the way of the sun. It is so irregular that it is impossible for man to devise a clock that will keep the sun's time. The sun accelerates and retards as no clock could be made to accelerate and retard. The sun is sometimes ahead of its schedule; at other times it is lagging behind; and at still other times it is breaking the speed limit in order to overtake itself, or, rather, to catch up with where it ought to be in the sky. In this last case it does not slow down quick enough, and, as a result, goes dashing ahead of where it ought to be. In fact, only four days in a year do the sun and the place where the sun ought to be happen to coincide. The remaining 361 days the sun is pothering around all over the shop. Man, being more perfect than the sun, makes a clock that keeps regular time. Also, he calculates how far the sun is ahead of its schedule or behind. The difference between the sun's position and the position where the sun ought to be if it were a decent, self-respecting sun, man calls the Equation of Time. Thus, the navigator endeavouring to find his ship's position on the sea, looks in his chronometer to see where precisely the sun ought to be according to the Greenwich custodian of the sun. Then to that location he applies the Equation of Time and finds out where the sun ought to be and isn't. This latter location, along with several other locations, enables him to find out what the man from Kansas demanded to know some years ago.

The Snark sailed from Fiji on Saturday, June 6, and the next day, Sunday, on the wide ocean, out of sight of land, I proceeded to endeavour to find out my position by a chronometer sight for longitude and by a meridian observation for latitude. The chronometer sight was taken in the morning when the sun was some 21 degrees above the horizon. I looked in the Nautical Almanac and found that on that very day, June 7, the sun was behind time 1 minute and 26 seconds, and that it was catching up at a rate of 14.67 seconds per hour. The chronometer said that at the precise moment of taking the sun's altitude it was twenty-five minutes after eight o'clock at Greenwich. From this date it would seem a schoolboy's task to correct the Equation of Time. Unfortunately, I was not a schoolboy. Obviously, at the middle of the day, at Greenwich, the sun was 1 minute and 26 seconds behind time. Equally obviously, if it