"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?" "Yas, suh," the darky replied, "Ah knows there is." "Go ahead and get it then," the observer asked, "and let me have a piece of string." He fastened the string to the bottom of the pole and awaited the return of Dan'l with the whitewash. In a moment the old negro came back with the pail. "Now," said the Forecaster, "I'm going to hold this string right at the end, and, holding it tightly, walk around the pole. What kind of a figure will that make?" "A circle," answered the two boys. "Right. Dan'l, you take the brush and whitewash a narrow line right behind my hand as I move the string round." Dan'l stooped down and rapidly painted in the circle, as the Forecaster moved the string. "Next," said the Weather Man, "we'll make another circle, a little closer in." "At any special distance, sir?" asked Anton. "No," was the reply. "It doesn't matter. Any distance at all will do." A second, and again a third circle was thus made. "Tie a piece of rope around the pole," was the next direction, "as high as you can reach." This only took a minute. "Now, boys," the Forecaster said, "all that you have to do is to watch when the shadow of the rope crosses those three circles. Put in a peg this evening when it crosses the inside one, then the middle and then the outside. To-morrow morning, mark with pegs the place where the shadow crosses the same circles on the other side, only, of course, it will cross the outer one first." "Then what shall we do, sir?" asked Anton. "Have you a long straight board?" he asked in reply. "Plenty of them," the younger lad answered. "Good. Well then, to-morrow morning lay that board so that its edge touches the two points where the shadow of the rope on the pole crossed the outer circle and let Dan'l whitewash a straight line joining the two points. Do the same with the second and with the inside circles." "Yes?" queried the lad eagerly, "and then?"