Another time I had not seen Thyriel for some days; we were both busy at our own pursuits in different parts of the island. She, as I learned afterwards, had been set to account for a new and somewhat peculiar odour that had recently begun to accompany the issue of vapour from a distant lava-well. I was engaged in timing a new and intermittent disturbance on the surface of the sea off the eastern shore, and trying to find whether it had any relationship to an intermittent fumarole which had recently broken out on the eastern slope of Lilaroma. I had kept watch for several days, and could find no synchronism in their periods, although I was convinced that there was a close connection between them, if there was not a common cause. I was feeling baffled and somewhat downcast; when suddenly there sprang up in me a sense of elation, if not of triumph, which continued for the rest of the day, although I still failed to discover the connection between the two phenomena. When I set out next day for the scene of my observations, I was joined by Thyriel, who explained that she had finished her task the day before and had now been detailed to assist me in mine. I then knew the cause of my thrill of joy, and told her of it. She had at that very hour not only discovered the source of the fumes in a new mineral that the leomoran had touched, but found that this new deposit was extraordinarily generative of electricity. It was this that had made her heart leap for joy and go out towards me. She had longed for my sympathy in her rejoicing, and unconsciously her filammu had energised in my direction. Between us we soon saw that there was a complicated periodicity in the alternations of my two phenomena; it needed several days’ observation to catch the rhythm, and for that reason I had been baffled at first. Before long I discovered the cause; as soon as a lava-well farther north had ceased to flow, they also ceased; it was the viscous intermittance of its stream opening and then closing two apertures below tide-line into the subterraneous fires that had regulated the rhythm of these new vents; the break in the lava-current, the rise and fall of the tide, and the rush of the breakers had made it complex. And the lava had finally closed both before it had ceased to flow.