ortunity for a
most interesting study."

"That is indeed the case, John," I replied. "Those coloured flames, for
instance, form a study in themselves, which some observers make their
particular hobby. As seen from the earth, they all appear some tint of
red; and, normally, according to measurements, they seem to extend a
distance of some 20,000 miles above the sun. They shift their position
very rapidly indeed; movements at the rate of 100 miles a second are
quite moderate compared with some which have been noted, yet one can
scarcely realise such rapidity of motion. Frequently, however, these
flames are seen to rise in immense masses to tremendous heights above
the sun's surface, evidently driven upwards by explosions of the most
intense energy. In 1888, for instance, one was observed which, in the
course of two hours, rose to a height of 350,000 miles before it broke
up; that is, at the rate of 50 miles a second all the time; but, as the
force would become less and less as the distance increased, at the
earlier part of the time the movement must have been far more rapid.
When the impetus derived from the explosive force is quite exhausted,
the top part of the mass of flame often spreads out like the top of a
tree, then breaks up and falls back into the sun in large flakes of
flame.

"It is supposed that these violent explosions are the cause of the spots
we so often see on the sun when observing it with our telescopes; and,
when looking at them in their earliest stage, we are probably looking at
a mass of flame _end on_, instead of seeing it in profile, as is the
case when the explosion occurs near the edge of the disc. The flames, as
examined by the spectroscope, appear to be largely composed of hydrogen
gas; and no doubt many other gases--some quite unknown to us--enter into
their composition. They are termed flames, but are more probably immense
volumes of incandescent gases. The corona itself is never seen twice
alike; its shape and size vary at every eclipse, but the variation runs
in a regular cycle from maximum to minimum.

"You will also observe that all around the corona, and extending a vast
distance beyond it on both sides, is a fainter pearly light. This is
what is termed the zodiacal light, and is believed to be the thinner
portion of the sun's atmosphere. We can see it from the earth
occasionally after the sun has set, extending far up into the sky in the
form of a semi-ellipse, the base of which is o