"From all appearances there will be a heavy sea," she went on.
"Just an ordinary bad night," he said coolly.
"Do the waves reach far up the lighthouse in a gale?" she persisted.
Then Brand grasped the situation firmly.
"So that your slumbers may be peaceful," he said, "I will call your kind attention to the fact that the Gulf Rock light has appeared every night during the past twenty-five years, or since a date some four years before you were born, Constance. It contains 4,000 tons of granite and is practically monolithic, as if it were carved out of a quarry. Indeed, I think its builder went one better than nature. Here are no cracks or fissures or undetected flaws. The lowest course is bolted to the rock with wrought-iron clamps. Every stone is dovetailed to its neighbors, and clasped to them with iron, above, below and at the sides. If you understand conic sections I could make clearer the scientific aspect of the structure, but you can take it from me you are far safer here than on a natural rock many times the dimensions of this column."
"That sounds very satisfactory," murmured Enid, sleepily.
"I am overwhelmed," said Constance, who grasped the essential fact that he had not answered her question.
Soon after nine o'clock he kissed them good-night. They promised not to sit up talking. As a guarantee of good behavior, Enid said she would ring the electric bell just before she climbed into her bunk.
The signal came soon and he was glad. He trusted to the fatigue, the fresh air, the confidence of the knowledge that he was on guard, to lull them into the security of unconsciousness.
The behavior of the mercury puzzled him. In the barometer it fell, in the thermometer it rose. Increasing temperature combined with low pressure was not a healthy weather combination in January. Looking back through the records of several years, he discovered a similar set of conditions one day in March, 1891. He was stationed then on the Northeast coast and failed to remember any remarkable circumstance connected with the date, so he consulted the lighthouse diary for that year. Ah! Here was a possible explanation. The chief-keeper, a stranger to him, was something of a meteorologist.