"Ah! that is one of the things which it has been difficult to determine. They appear to be modifications of the trade winds. While, as stated, the northeast winds blow during the periods mentioned, they have the southwest monsoons, which blow from April to October. As these violent winds are the most tempestuous during the period when the sun crosses the equator, it has been argued that it is due to the action of the sun being in such a position that its rays strike the earth in the center of its rotation, thus heating up the air and causing it to rise rapidly along the middle belt."
"Is that what we understand by the equinoctial storms?"
"The equinoctial storms come in March and September, when the days and nights are of equal length."
"I was told by a teacher that the summers are longer north of the equator than south of it; is that true?"
"Yes; the summer north of the equator is about seven and a half days longer."
"What is the cause of that?"
"The earth is at its greatest distance from the sun during the summer months, and the angular motion of the earth in its orbit is slower. The result is, that the interval from the March to the September equinoxes is greater than from September to March."
Harry made his way through the violent wind and rain to the boat shed. He came back with a sorry-looking countenance. "I am afraid everything is soaked beyond recovery." He was almost on the verge of tears.
Before noon the rain abated somewhat, but the winds still blew strongly, and when they ventured out to take stock of their surroundings, George was the first to notice the disappearance of the flag on Observation Hill. Rushing in to the Professor, he cried: "Our flag is gone."
Harry was at the boathouse, and when George went down to inform him of the new calamity, he was almost heart-broken. The Professor, however, was not in the least perturbed. He laughingly chided them and soon restored the boys to their usual gay and happy demeanor.