Free Tramp Royale by Robert A. Heinlein

enterprise." A third quick answer is that merchant shipping is no longer a major factor in war because the next war will be settled from the air in a matter of hours or days.
    I am sorry to say that I seem to have mislaid the right answer.
     
    The Gulf Shipper arrived off the Atlantic end of the Panama Canal early Saturday morning the 21st, stopped just long enough to pick up the pilot and his handling crew and to drop the purser, then started through the Canal. Passengers could, if they wished, get off with the purser, spend the day shopping and sightseeing, travel across the Isthmus by bus, and join the ship that evening on the Pacific side.
    None of us did so. Ticky had never seen the Canal before, but neither had she ever seen Colon and Panama City and the U.S. settlements, Cristóbal and Balboa, adjacent to them. She was torn between the desire to see the first foreign port in our trip and a desire to see the Canal; I persuaded her to see the Canal.
    I swear on a stack of wheat cakes that I was not motivated by a desire to keep her away from the bazaars. It is true that the shops of Colon and of Panama City have an effect on all women and some men much like that of a bed of fresh catnip on a cat-and the bargains often are real bargains, for Panama City is a free port. No, like a total eclipse of the sun, the experience of transiting the Panama Canal is one that should not be missed if available. There is nothing else like it in the world . . . and I am not forgetting the Suez Canal.
    I still have scars on my arms from sunburn acquired more than a quarter of a century ago when I first went through the big ditch. I knew at the time that I was getting sunburned but I could not bring myself to stop looking and go below. Since then I have seen it many times-and I still can't stop looking.
    Any atlas, world almanac, or encyclopedia will provide a winter's supply of sound, chewy facts about the Panama Canal, tonnages, tolls collected, yards of earth moved, and so forth. They are well worth reading but we will not repeat them here. The Canal was started by the French in 1882; you can still see the old French Canal slicing slaunchwise into the channel we cut. Yellow fever and more bad luck than any man ought to have put a stop to the French attempt. We bought the franchise and, with almost indecent haste, recognized a Panamanian revolutionary government which seceded from Colombia in 1903, signed a treaty with the new government and started work again in 1904. Ten years later the first ship went through.
    The Canal is fifty miles long and runs northwest to southeast across the twisted isthmus in such a fashion that the trip from the Atlantic to the Pacific (i.e., to the west ) winds up twenty-seven miles farther to the east. This has to be seen on a map to be understood; it is as silly as the fact that Los Angeles is east of Reno. Sea level is a couple of feet higher on the Pacific side than on the Atlantic side but this odd fact is swallowed up by the fact that the major portion of the Canal is eighty-five feet higher than either ocean. Three sets of locks at each end perform the improbable task of lifting and lowering ships of fifty thousand tons or more the height of an eight-story building.
    There has been a lot of agitation for a sea-level canal, through Nicaragua or elsewhere. One glance at any one of the locks of the Panama Canal is enough to show why; one pony-sized A-bomb anywhere near one of the locks would put the entire Canal out of use for months or years and leave our navy and merchant marine with a nice, long, chilly trip around the Horn in order to get from one coast to the other. You will correctly assume that the Canal Zone contains anti-aircraft and radar installations-but the bomb need not be delivered by air; it can be in the hold of a ship flying the flag of Ruritania, or even the U.S. flag. There are more than seven thousand ships going through the Canal each year and the only known way to inspect a ship