The year 1906 was one of bad weather, rendering frequent approach impossible. During this season the men landed only thirty-nine times and toiled for 152 hours, while the sum of their achievement was the least throughout the whole seven years which the tower occupied in its erection. The building is solid for about 30 feet above the rock, and in 1908 the construction of the tower proper was commenced. The base is circular, with a diameter of 33¾ feet; but the tower itself is of octagonal form, with a diameter at the base of 28 feet, tapering slightly to the top. One notable feature in connection with the work was the utilization of electricity for the operation of the derrick, which was driven by a petrol motor coupled thereto. This was supplemented in times of pressure with another derrick, driven by current generated on the steamer, from which a cable trailed to the rock. Altogether 4,180 tons of masonry were transported to the rock and set in position. During the seven years the work was in progress, from the first landing to the final withdrawal of the workmen, 449 landings were made and 2,937 hours of work put in. The largest annual aggregate of labour was in 1911, when 70 landings were made and 400 hours turned to useful purpose. The tower, which is of imposing appearance, has six floors for the convenience of the keeper, stores, etc. The apartment immediately beneath the lantern contains the fog-signalling apparatus, which comprises a siren driven by air which is compressed for the purpose by means of a fourteen horse-power petrol motor. The signal is as follows: Three blasts of one and a half seconds’ duration with intervening intervals of one and a half seconds, followed by a silent period of fifty-two and a half seconds, one cycle thus being emitted every minute. The light, which is thrown from an elevation of 110¼ feet above high-water, throws groups of three red flashes at intervals of fifteen seconds, and has a maximum range of twenty miles in very clear weather.