s should be equally ready to
discuss subjects they had not inquired into.

Another very remarkable instance was afforded by Mr. Reddie's treatment
of the subject of comets. And here, by the way, I shall quote a remark
made by Sir John Herschel soon after the appearance of the comet of
1861. 'I have received letters,' he said, 'about the comets of the last
few years, enough to make one's hair stand on end at the absurdity of
the theories they propose, and at the ignorance of the commonest laws of
optics, of motion, of heat, and of general physics, they betray in their
writers.' In the present instance, the correspondence showed that the
paradoxist supposed the parabolic paths of some comets to be regarded by
astronomers as analogous to the parabolic paths traversed by
projectiles. He expressed considerable astonishment when I informed him
that, in the first place, projectiles do not travel on truly parabolic
paths; and secondly, that in all respects their motion differs
essentially from that which astronomers ascribe to comets. These last
move more and more quickly until they reach what is called the vertex of
the parabola (the point of such a path which lies nearest to the sun):
projectiles, on the contrary, move more and more slowly as they approach
the corresponding point of their path; and further, the comet first
approaches and then recedes from the centre of attraction--the
projectile first recedes from and then approaches the attracting centre.

The earth-flatteners form a considerable section of the paradoxical
family. They experienced a practical rebuff, a few years since, which
should to some degree have shaken their faith in the present chief of
their order. To do this chief justice, he is probably far less confident
about the flatness of the earth than any of his disciples. Under the
assumed name of Parallax he visited most of the chief towns of England,
propounding what he calls his system of zetetic astronomy. Why he should
call himself Parallax it would be hard to say; unless it be that the
verb from which the word is derived signifies primarily to shift about
or dodge, and secondarily to alter a little, especially for the worse.
His employment of the word zetetic is less doubtful, as he claims for
his system that it alone is founded on the true seeking out of Nature's
secrets.

The experimental basis of the theory of Parallax is mainly this: Having
betaken himself to a part of the Bedford Canal, where t