"We left Singapore at seven in the morning," said Frank, "and we had eighty miles to go to reach the equator. The steamer is running ten miles an hour, and according to my calculation we should be on the equator about three o'clock."
Fred was of the same opinion; and it was determined that they would watch closely from two till four o'clock, and see if the southern hemisphere was in any way unlike the Northern one; and so they watched while the steamer moved on and on towards the south. A little past three in the afternoon the Doctor told them they were probably in the region of no latitude, and that the equator was under their feet.
"I tell you what, Frank," said Fred, "it may be all my imagination, but it seems to me that the sea has a different appearance here from anything I have yet seen."
"What is that?"
"Why, you know that everywhere else when we are at sea we appear to be in a hollow or basin, and the horizon line of the water is higher than we are. Now, as I look off from the steamer, it seems to me that the world rounds away from us, and if my eyesight was strong enough I could see the North and the South Poles. Instead of being in a hollow, as we have always appeared to be heretofore, I seem to be on a great globe, or the summit of a rounded hill."
Frank thought he had the same sensation, but not so strongly as Fred. They appealed to the Doctor, who said that the feeling was mostly imaginary, and grew out of the knowledge that they were crossing the equator. "But there is sometimes a condition of the atmosphere," he added, "which produces the appearance you describe. In all the time I have passed at sea I have seen it only on a few occasions—perhaps three or four in all. There is a suggestion of it at this moment, I observe, and your imagination has done the rest.
"And you may consider yourself fortunate," he continued, "that you are not making an old-fashioned voyage of twenty or thirty years ago."
"Why so?" Frank asked.