Explaining The Seasons
The seasons are caused by the Sun’s circuit round the Earth in
a spiral ecliptic. In the Winter Solstice (December 21st), the Sun
is vertical over the Tropic of Capricorn. Looking South from London,
he appears to make a small circuit in the Southern sky, during the
same period he is seen to cross the sky at almost overhead in Cape
Town, thus causing Summer in the Southern Hemisphere. In the
Summer Solstice (June 21st), the Sun is vertical over the Tropic of
Cancer, (nearly overhead in London), while looking North from Cape
Town, he appears to make a small circuit in the Northern sky, causing
Winter in the Southern and Summer in the Northern Hemisphere.
The supposition that the seasons are caused by the Earth’s annual
motion round the Sun at a mean distance of 92,500,000 of miles, is
According to Piazzi the size of the Sun is in proportion to the
Earth, “as 329,360 to 1, the diameter exceeds that of the Earth
112 times.” The Earth appears, as Biot says, by this statement,
“a mere grain of sand, as compared to the Sun.” This enormous
expanse of light focused on a rotating “ grain of sand,” at the distance
of 92 millions of miles, would cause the same season throughout it.
The paltry few miles, in comparison that separates London from
Cape Town could never cause diverse seasons, neither would the
distance from London to the Riviera justify the difference in the
climate that characterises the two places.