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]
The navy that invested the harbor entertained no illusions on that score. It had not dared the attempt to force the passages of Narragansett. It would not dare to force the passages of Boston. As at Narragansett, its business was to occupy the defenders and wear them out while the army fell on them and on Boston from the land.[92]