Cyrus Harding even observed that if by chance the communication between the unknown and the tenants of Granite House had ever been established through the granite, and if Top's instinct had as it were felt it, there was no further sign of it during this period. The dog's growling had entirely ceased, as well as the uneasiness of the orang. The two friends--for they were so--no longer prowled round the opening of the inner well, nor did they bark or whine in that singular way which from the first the engineer had noticed. But could he be sure that this was all that was to be said about this enigma, and that he should never arrive at a solution? Could he be certain that some conjuncture would not occur which would bring the mysterious personage on the scene? Who could tell what the future might have in reserve? At last the winter was ended, but an event, the consequences of which might be serious, occurred in the first days of the returning spring. On the 7th of September, Cyrus Harding, having observed the crater, saw smoke curling round the summit of the mountain, its first vapours rising in the air. CHAPTER FIFTEEN. THE AWAKENING OF THE VOLCANO--THE FINE SEASON--CONTINUATION OF WORK--THE EVENING OF THE 15TH OF OCTOBER--A TELEGRAM--A QUESTION--AN ANSWER-- DEPARTURE FOR THE CORRAL--THE NOTICE--THE ADDITIONAL WIRE--THE BASALT COAST--AT HIGH TIDE--AT LOW TIDE--THE CAVERN--A DAZZLING LIGHT. The colonists, warned by the engineer, left their work and gazed in silence at the summit of Mount Franklin. The volcano had awoke, and the vapour had penetrated the mineral layer heaped up at the bottom of the crater. But would the subterranean fires provoke any violent eruption? This was an event which could not be foreseen. However, even while admitting the possibility of an eruption, it was not probable that the whole of Lincoln Island would suffer from it. The flow of volcanic matter is not always disastrous, and the island had already undergone this trial, as was shown by the streams of lava hardened on the northern slopes of the mountain. Besides, from the shape of the crater--the opening broken in the upper edge--the matter would be thrown to the side opposite the fertile regions of the island. However, the past did not necessarily answer for the future. Often, at the summit of volcanoes, the old craters close and new ones open. This has occurred in the two hemispheres--at Etna, Popocatepetl, at Orizaba-- and on the eve of an eruption there is everything to be feared. In fact, an earthquake--a phenomenon which often accompanies volcanic eruptions--is enough to change the interior arrangement of a mountain, and to open new outlets for the burning lava.