that can be
said about it. Every one knew that this height varies according to the
latitude of the place where the observation is taken. But the only zones
of the globe where the moon reaches her zenith--that is to say, where
she is directly above the heads of the spectators--are necessarily
comprised between the 28th parallels and the equator. Hence the
important recommendation given to attempt the experiment upon some point
in this part of the globe, in order that the projectile may be hurled
perpendicularly, and may thus more quickly escape the attraction of
gravitation. This was a condition essential to the success of the
enterprise, and public opinion was much exercised thereupon.

As to the line followed by the moon in her revolution round the earth,
the Observatory of Cambridge had demonstrated to the most ignorant that
it is an ellipse of which the earth occupies one of the foci. These
elliptical orbits are common to all the planets as well as to all the
satellites, and rational mechanism rigorously proves that it could not
be otherwise. It was clearly understood that when at her apogee the moon
was farthest from the earth, and when at her perigee she was nearest to
our planet.

This, therefore, was what every American knew whether he wished to or
no, and what no one could decently be ignorant of. But if these true
principles rapidly made their way, certain illusive fears and many
errors were with difficulty cleared away.

Some worthy people maintained, for instance, that the moon was an
ancient comet, which, whilst travelling along its elongated orbit round
the sun, passed near to the earth, and was retained in her circle of
attraction. The drawing-room astronomers pretended to explain thus the
burnt aspect of the moon, a misfortune of which they accused the sun.
Only when they were told to notice that comets have an atmosphere, and
that the moon has little or none, they did not know what to answer.

Others belonging to the class of "Shakers" manifested certain fears
about the moon; they had heard that since the observations made in the
times of the Caliphs her movement of revolution had accelerated in a
certain proportion; they thence very logically concluded that an
acceleration of movement must correspond to a diminution in the distance
between the two bodies, and that this double effect going on infinitely
the moon would one day end by falling into the earth. However, they were
obliged to reassure thems