act 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 s