heory that the theory itself was simple, whereas it had become so
confusing that not merely young learners, but the most profound
mathematicians, were baffled when they tried to unravel the motions of
the planets.

I think the figure pretty well explains itself. All I need mention is,
that while the shape and position of each path is correctly shown, the
size of the sun at center is immensely exaggerated. A mere pin point,
but shining with star-like splendor, would properly represent him.
As for the figures of the earth and Mars, they are still more
tremendously out of proportion. The cross-breadth of the lines
representing these planets' tracks is _many times_ greater than the
breadth of either planet on the scale of the chart.

On September 5 the earth and Mars came to the position shown at E and
M. You observe that they could not be much nearer. It is indeed very
seldom that Mars is so well placed for observation. His illuminated
face was turned toward the dark or night half of the earth, so that he
shone brightly in the sky at midnight, and can be well studied with
the telescope.

When Galileo turned toward Mars the telescope with which he had
discovered the moons of Jupiter, the crescent form of Venus, and many
other wonders in the heavens, he was altogether disappointed. His
telescope was indeed too small to show any features of interest in
Mars, though the planet of war is much nearer to us than Jupiter. Mars
is but a small world. The diameter of the planet is about 4,400 miles,
that of our earth being nearly 8,000. Jupiter, though much farther
away, has an immense diameter of more than 80,000 miles to make
up, and much more than make up, for the effect of distance. With his
noble system of moons he appears a remarkable object even with a
small telescope, while Mars shows no feature of interest even with
telescopes of considerable size.

It was not, then, till very powerful telescopes had been constructed
that astronomers learned what we now know about Mars.[4]

[Footnote 4: See the "Moons of Mars" in "Letter Box" Department]

It is found that his surface is divided into land and water, like the
surface of our own earth. But his seas and oceans are not nearly so
large compared with his continents and lands. You know that on our own
earth the water covers so much larger a surface than the land that
the great continents are in reality islands. Europe, Asia and Africa
together form one great island; North