explained that it meant the angle formed by the inclination of two
straight lines drawn from either extremity of the earth's radius
to the moon. On doubts being expressed as to the correctness of
this method, they immediately proved that not only was the mean
distance 234,347 miles, but that astronomers could not possibly
be in error in their estimate by more than seventy miles either way.

To those who were not familiar with the motions of the moon,
they demonstrated that she possesses two distinct motions, the
first being that of rotation upon her axis, the second being
that of revolution round the earth, accomplishing both together
in an equal period of time, that is to say, in twenty-seven and
one-third days.

The motion of rotation is that which produces day and night on
the surface of the moon; save that there is only one day and one
night in the lunar month, each lasting three hundred and
fifty-four and one-third hours. But, happily for her, the face
turned toward the terrestrial globe is illuminated by it with an
intensity equal to that of fourteen moons. As to the other
face, always invisible to us, it has of necessity three hundred
and fifty-four hours of absolute night, tempered only by that
"pale glimmer which falls upon it from the stars."

Some well-intentioned, but rather obstinate persons, could not
at first comprehend how, if the moon displays invariably the
same face to the earth during her revolution, she can describe
one turn round herself. To such they answered, "Go into your
dining-room, and walk round the table in such a way as to always
keep your face turned toward the center; by the time you will