It is not surprising that the ceaseless attacks of the waves should have left their traces at last. The light had been burning for about twenty years, when tremors and quakings, similar to those observed in connection with Smeaton’s Eddystone tower, were reported to the authorities. Sir James Douglass visited the rock, and made a minute inspection. It was apparent that the lighthouse demanded extensive overhauling and strengthening if it were to be preserved. In fact, this was the only feasible course of action, as there was not another suitable spot whereon a new structure could be raised. The Eddystone had been completed, and as the same tackle was available, the protective work was undertaken at once. In conjunction with this enterprise, the engineer also advocated an increase in the height of the tower. His plans met with approval, and an ingenious means of strengthening the existing building was evolved. Virtually it comprised the erection of a new tower around the old shaft, and connected to the latter, so as to form one homogeneous structure. In order to strengthen the foundations, massive blocks of masonry were sunk into the rock, cemented, and held in position by heavy bolts. From the masons’ point of view, the task of overhauling was more exciting and dangerous than that which had attended the erection of the original tower; for the men had to toil on narrow, swinging platforms, cutting notches in the face of every stone in the existing structure to receive dovetails on the blocks of the new outer shell. Thus the latter were dovetailed to adjacent blocks on five out of their six faces. A massive chain was slung round the upper part of the tower, from which life-lines hung down to the men working below. A man was stationed as a lookout. When he saw a breaker approaching he gave a signal; each man clutched his life-rope tenaciously and retained his foothold as best he could on his perilous perch while the water swept over him. Often the men were submerged by a rushing wave, and when the water subsided shook themselves like dogs emerging from the water. But the provision of the life-ropes prevented serious injury and loss of life, although the masons at times were considerably knocked about. The tower has been given an enormous, massive, cylindrical base, while the shaft is solid to the entrance level, except for the usual water-tanks. The attachment of the outer shell reinforced it remarkably, the walls at the entrance being increased to a thickness of 8 feet. The addition of the four extra floors elevated the light by a further 40 feet, the focal plane now being 163 feet above high-water. The light, of 622,500 candle-power, visible for eighteen miles, is a white group-flash, there being two flashes, each of four seconds’ duration, with an intervening eclipse of five seconds, while the groups are separated by intervals of forty-seven seconds.