Bell Rock was only one of twenty lighthouses Robert Stevenson helped to
build, but it was by far the most difficult one ... and even to-day,
after it has been lighted for more than a hundred years, it still
remains unique--a monument to his skill.

Bell Rock was practically a reef completely submerged at full tide and
only a few feet of its crest visible at low water. To raise a tower on
it meant placing a foundation under water, a new and perilous
experiment.

"Work upon the rock in the earliest stages was confined to the calmest
days of the summer season, when the tides were lowest, the water
smoothest, and the wind in its calmest mood. Under such conditions the
men were able to stay on the site for about five hours....

"One distinct drawback was the necessity to establish a depot some
distance from the erecting site. Those were the days before steam
navigation, and the capricious sailing craft offered the only means of
maintaining communication between rock and shore, and for the conveyance
of men and materials to and fro....

"A temporary beacon was placed on the reef, while adjacent to the site
selected for the tower a smith's forge was made fast, so as to withstand
the dragging motion of the waves when the rock was submerged. The men
were housed on the _Smeaton_, which, during the spells of work on the
rock, rode at anchor a short distance away in deep water." [Footnote:
Talbot, "Lightships and Lighthouses."]

Once the engineers were all but lost when the _Smeaton_ slipped her