ke it as simple as I can, though, I
warn you, a hurricane isn't a subject that can be explained in a
sentence or two.

"You know that summer and winter weather are different. You ought to be
able to see that summer and winter winds are different. The difference
in seasons is caused by the respective positions of the northern and
southern hemispheres to the sun. The greater the heat, the greater the
atmospheric changes. Hurricanes are great whirls caused by violent
changes of the air. Therefore hurricanes come only in the summer."

"That's clear and easy!" declared the boy, delighted that he was able to
follow the explanation.

"Now, as to why hurricanes strike here and nowhere else. I'll try and
explain that, too. There is a belt of ocean, just north of and on the
equator, known as the 'doldrums,' where it is nearly always calm, and
very hot. There is also a belt of air running from Southern Europe to
the West Indies where the north-east trade winds blow all the year
round. Between this perpetual calm of the doldrums and the perpetual
wind of the trades is a region of atmospheric instability.

"Now, consider conditions to the west of us. The Caribbean Sea and the
Gulf of Mexico, together, form what is almost a great inland sea with
the West Indian Islands as its eastern shore. The trade winds do not
reach it. The Pacific winds do not reach it, for they are diverted by
the high ranges of Central America. The winds from North America do not
reach it, because these always turn northwards on reaching the
Mississippi Valley and leave the United States by the St. Lawrence
Valley.

"So, Stuart, you can see that the Caribbean Sea and the Gulf of Mexico
have over them, in summer, a region of air, little disturbed by wind,
not far from the Equator and which, therefore, becomes steadily heated
and steadily saturated by the evaporation from the body of water
below."

"Yes," agreed the boy, "I can see that."

"Very good. Now, such a steady heating of one section of air is bound to
disturb the balance of the atmosphere. This disturbance, moreover, must
be acted upon by the rotation of the earth. Just as all the weather in
the United States comes from the west and travels eastwards, so the
track of hurricane origins travels eastwards during the course of a
summer.

"For this reason, West Indian hurricanes in June generally have their
origin west of Jamaica, July hurricanes east of Jamaica, August
hurricanes in the eastern C