cleared all was swept away.  Then the spirit of the builder wavered, and he began to doubt that any structure built by men could withstand the powers of nature at Minot’s Ledge.  But, in time, the truth appeared.  A bark, the New Eagle, heavy laden with cotton, had been swept right over the reef, and grounded at Cohasset.  Examination showed that she had carried away in her hull the framework of the new tower.  Three years’ heart-trying work were necessary before the first cut stone could be laid upon the rock.  In the meantime, on a great table at Cohasset, a precise model of the new tower was built, each stone cut to the exact shape, on a scale of one inch to the foot, and laid in mortar.  This model completed, the soil on the hillside near by was scraped away.  The granite rock thus laid bare was smoothed and leveled off into a great flat circle, and there, stone by stone, the tower was built exactly as in time it should rise in the midst of the seething cauldron of foam three miles out at sea.  While the masons ashore worked at the tower, the men at the reef watched their chance, and the moment a square yard of ledge was out of water at the fall of the tide, they would leap from their boats, and begin cutting it.  A circle thirty feet in diameter had to be leveled, and iron rods sunk into it as anchorages for the masonry.  To do that took just three years of time, though actually less than twenty-five days of working time.  From the time the first cut stone was laid until the completion of the tower, was three years and three months, though in all there were but 1102 working hours.

One keeper and three assistants guard the light over Minot’s Ledge.  Three miles away across the sea, now blue and smiling, now black and wrathful, they can see the little group of dwellings on the Cohasset shore which the Government provides for them, and which shelter their families.  The term of duty on the rocks is two weeks; at the end of each fortnight two happy men go ashore and two grumpy ones come off; that is, if the weather permits a landing, for keepers have been stormbound for as long as seven weeks.  The routine of duty is much the same in all of the lighthouses.  By night there must be unceasing watch kept of the great revolving light; and, if there be other lights within reach of the keeper’s glass, a watch must be kept on them as well, and any eclipse, however brief, must be noted in the lighthouse log.  By day the lens must be rubbed laboriously with a dry cloth until it shines like the facets of a diamond.  Not at all like the lens we are familiar with in telescopes and cameras is this scientifically contrived device.  It is built up of planes and prisms of the finest flint glass, cut and assembled according to abtruse mathematical calculations so as to gather the rays of light from the great sperm-oil lamp into parallel rays, a solid beam, which, in the case of Minot’s Ledge light, pierces the night to a distance of fifteen miles.  On foggy days, too, the keepers must toll the fog-bell, or, if the light be on the mainland, operate the steam siren which sends its hoarse bellow booming through the gray mist to the alert ears of the sailor miles away.