One of our 16-inch Coast Defence Guns on a disappearing mount
Height of gun as compared with the New York City Hall
[CHAPTER IV]
Guns and Super-Guns
When the news came that big shells were dropping into Paris from a gun which must be at least seventy miles away, the world at first refused to believe; then it imagined that some brand-new form of gun or shell or powder had been invented by the Germans. However, while the public marveled, ordnance experts were interested but not astonished. They knew that it was perfectly feasible to build a gun that would hurl a shell fifty, or seventy-five, or even a hundred miles, without involving anything new in the science of gunnery.
SHOOTING AROUND THE EDGE OF THE EARTH
But if such ranges were known to be possible, why was no such long-distance gun built before? Simply because none but the Germans would ever think of shooting around the edge of the earth at a target so far away that it would have to be as big as a whole city to be hit at all. In a distance of seventy miles, the curve of the earth is considerable. Paris is far below the horizon of a man standing at St. Gobain, where the big German gun was located. And if a hole were bored from St. Gobain straight to Paris, so that you could see the city from the gun, it would pass, midway of its course, three thousand, seven hundred and fifty feet below the surface of the earth. With the target so far off, it was impossible to aim at any particular fort, ammunition depot, or other point of military importance. There is always some uncertainty as to just where a shell will fall, due to slight differences in quality and quantity of the powder used, in the density of the air, the direction of the wind, etc. This variation is bad enough when a shell is to be fired ten miles, but when the missile has to travel seventy miles, it is out of the question to try to hit a target that is not miles in extent.
Twenty years before the war our Ordnance Department had designed a fifty-mile gun, but it was not built, because we could see no possible use for it. Our big guns were built for fighting naval battles or for the defense of our coasts from naval attacks, and there is certainly no use in firing at a ship that is so far below the horizon that we cannot even see the tips of its masts; and so our big guns, though they were capable of firing a shell twenty-seven miles, if aimed high enough, were usually mounted in carriages that would not let them shoot more than twelve or fifteen miles.