The integral parts of this building were prepared by three different contractors, were fitted together, and the building set up temporarily, on the mainland, so as to facilitate erection at the site. The work was started in 1876, the first move being the provision of a platform about 80 feet square and 12 feet above low-water, from which to conduct operations. The lower piles were driven about 10 feet into the live coral reef. Extreme care was observed during this operation, the pile after every stroke of the driver being tested with a plumb-line, to make sure that it was being sent home absolutely vertically. If it diverged, however slightly, from the perpendicular, the error was corrected immediately. When the piles had been driven to the requisite depth, the tops were levelled to the height of the most deeply driven pile; then the horizontal members were placed in position, followed by the diagonal bracing. [Illustration: THE BONITA POINT LIGHTHOUSE OFF THE CALIFORNIAN COAST. While the tower is only 21 feet in height, its position on a lofty cliff gives the light of 27,000 candle-power a range of 17 miles.] This task occupied some two months, and then a spell of bad weather broke over the coast, interspersed with brief intervals of smooth seas and calms. As the land depot was four miles away, this involved frequent journeys to and fro for the workmen, who had to be brought off the work upon the slightest sign of rough weather. To eliminate the interruptions arising from this procedure, tents were despatched to the site and pitched on the wooden platform, so that the men might reside there. At times their situation was alarming; the heavy seas rushed and tumbled among the piles beneath the crazy perch, and the men were always on tenterhooks lest a hurricane, such as is experienced often in this region, should bear down upon them and carry the whole colony away. When work was in progress, they did not realize their lonely, perilous position so much, since their minds were otherwise occupied; but it was the enforced periods of idleness, often lasting several days on end, which made them grow despondent, as they were virtually imprisoned, and there was very little space in which to obtain exercise. The material was brought out in lighters towed by a steam-launch, on which steam was kept up day and night, because the material had to be sent out at any moment when the conditions were favourable. Again, this “standing by” was imperative, in case a sudden call for assistance should be given by the little isolated community when faced with disaster during a storm. When the men got the keepers’ quarters completed, their minds became easier, as they were now in possession of a more stable camp. The superstructure advanced at a rapid rate, and the light was shown for the first time on June 15, 1878.