Anton described the principles that the boys had used and especially the means adopted to ensure that the pole should be upright.
"Why don't you fix it so that you won't have to measure the length of the shadow every day?" queried the Forecaster. "It's quite easy when you know how."
"Won't you show us?" responded Anton.
"Certainly," the old Weather Man answered, getting out of his buggy. "I see," he continued, "you've got hold of the idea that when the sun casts the shortest shadow it must be true noon, because the sun is half-way between the longest shadow and the shortest. That means, of course, that the sun is at the meridian."
"Yes, sir."
"It would be much the same thing, wouldn't it, if you measured half the distance between the points on the horizon where the sun rose and the sun set?"
Ross thought for a moment.
"Yes," he said, "I suppose it would. But is that always the same?"
"How can it be anything else?" the Forecaster asked. "In winter the day is short and in summer it is long, but the meridian plane is always the same—that is, excepting for certain very small astronomical variations which would make no difference to you in the matter of measuring time. Let's get the meridian plane, first. Dan'l, do you suppose there's a pail of whitewash in the barn?"