The tide had long since turned; it was rising; slowly and continuously it was lipping nearer and nearer--slowly but with certainty was it coming; and I perceived all this! I had many a fall, as I scrambled to and fro; and my knees were bleeding from contact with the hard stones; but these were not matters to grieve about, nor was it a time to give way to hardships, however painful to endure. A far greater hardship threatened--the loss of life itself--and I needed no urging to make me persevere with my work. I had raised the pile up to the height of my head before the tide had yet risen over the rocks, but I knew that this would not be high enough. Two feet more was wanted to bring the top of my cairn on a level with high-water mark; and to accomplish this I slaved away without thinking of a moment's rest. The work as it went on became more difficult. The loose stones that lay near had all been used, and I was obliged to go far out on the reef to procure others. This led to a great many severe falls, in which both my hands and knees were badly bruised; besides, it prevented me from making rapid progress. There was another cause that delayed me. At the height of four feet the pile was on a level with the crown of my head, and it was with difficulty I could place the stones higher up. Each one occupied me for minutes, and sometimes a heavy boulder which I had succeeded in getting up, would roll back again, endangering my limbs in its fall. In fine, after labouring for a long time--two hours, or more--my work was brought to a termination. Not that it was done--far from it. Unfortunately, it was not terminated, but _interrupted_. What interrupted it I need hardly tell you, as you will guess that it was the _tide_. Yes, it was the tide, which, as soon as it had fairly begun to cover the stones, seemed to rush over them all at once. It did not recoil, as I have often seen it do upon the beach. There it flows in gradually, wave after wave; but upon the reef--the surface of which was nearly of equal height--the water, at the first rush, swept all over the rocks, and was soon of a considerable depth. I did not leave off my exertions until long after the rocks were covered. I worked until I was knee deep in water, bending down to the surface, almost diving under it, detaching great stones from their bed, and carrying them in my arms towards the pile. I toiled away, with the spray spitting in my face, and sometimes great sheets of it breaking over my body, until I feared it would drown me--toiled on till the water grew so deep and the sea so strong, that I could not longer keep my footing upon the rocks; and then, half-wading, half-swimming, I brought my last stone to the heap, and hoisted it up. Climbing after, I stood upon the highest point of the battery I had erected, with my right arm closely hugging the shaft of the signal. In this attitude, and with trembling heart, I watched the inflow of the tide. CHAPTER ELEVEN.