The falling lights opened, like monster flowers, into glaring, spectrally white flame just before they reached the earth. All the harbor where they fell stood revealed as in a lightning flash; but this flame did not go out like a lightning flash. It burned, steady, inextinguishable, for long minutes. They were star-bombs that were being dropped on the forts by the great war-fowl, the iron breasted aeroplanes. The white lights glaring below, and the hanging lights in the air that stood like a lighted staff, pointed out the forts to the hooded cannon of their iron sisters out at sea. Fired at from sea and sky, the forts replied and shook the earth. Faster and faster hurried the fire from the hidden ocean. Five ships were firing their secondary batteries to destroy an out-lying searchlight at a range of 6,000 yards. It was said afterward that at least five hundred projectiles were expended at that one mark alone.[90] In a great semicircle around Boston Harbor, from Nahant out to sea and curving in again toward Cohasset on the south, lay the flaming, roaring line, firing at the defenses all night long, till the dawn began to whiten. And behind Boston, inland, the other great armed semicircle was contracting steadily, swiftly. VII THE INVESTMENT OF BOSTON Boston Harbor should have been impregnable to attack from the sea. Had Nature been a modern army engineer, she could not have constructed an oceanic gate more perfectly designed for modern defense against modern ships. One might picture Boston as being protected by two great claws that curve seaward and wait there on guard, pointing toward each other. The northern claw would be Winthrop peninsula with its beach and summer cottages. The southern one would be the long, narrow arm of land that has famous Nantasket Beach on it, and ends northward at Point Allerton. Between these two claws, a prodigal hand has scattered islands. From Deer Island, lying in the north close under Winthrop, to George’s Island in the south, they form a stone wall with gaps that are the channels. Far out, grouped around the portal, the sea is sown with ledges and rocks whose kelp beards stream in an ever-heaving sea. Here are the Brewsters, the Devil’s Back, the Graves, the Roaring Bulls. Within, there is a glorious harbor great enough for a world’s armada. But the entrance is a Pass of Thermopylæ. Commanding that pass and all approaches far out to sea with zones of fire whose intersecting circles marked rings of sure destruction, were defenses honestly built. They were ready to receive and withstand that climax of destructiveness which man’s science has embodied in the conical steel projectile fired from the rifled gun.[91]