h 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.

"Such little incidents as we have met with this morning only give us
variety. We need something of this kind to add zest to life. Just
imagine what life would be if everything turned out just as you wanted
it or willed it? You would commit suicide within a week."

The boys smiled, but at the same time their eyelids did double duty in
the blinking line for a little while.

George straightened himself out and looked up the hill. "Well, I am
going for that flag whether it blows or not," and he started for