ny, but it is undeniable
that the distance separating the Earth from the Moon is measured with
greater care than, for instance, the length of the road from Paris to
Marseilles, or the weight of a pound of sugar at the grocer's. (And we
may add without comment, that the astronomers are incomparably more
conscientious in their measurements than the most scrupulous
shop-keepers.)

Had we conveyed ourselves to the Moon in order to determine its distance
and its diameter directly, we should have arrived at no greater
precision, and we should, moreover, have had to plan out a journey
which in itself is the most insurmountable of all the problems.

The Moon is at the frontier of our little terrestrial province: one
might say that it traces the limits of our domain in space. And yet, a
distance of 384,000 kilometers (238,000 miles) separates the planet from
the satellite. This space is insignificant in the immeasurable distances
of Heaven: for the Saturnians (if such exist!) the Earth and the Moon
are confounded in one tiny star; but for the inhabitants of our globe,
the distance is beyond all to which we are accustomed. Let us try,
however, to span it in thought.

A cannon-ball at constant speed of 500 meters (547 yards) per second
would travel 8 days, 5 hours to reach the Moon. A train started at a
speed of one kilometer per minute, would arrive at the end of an
uninterrupted journey in 384,000 minutes, or 6,400 hours, or 266 days,
16 hours. And in less than the time it takes to write the name of the
Queen of Night, a telegraphic message would convey our news to the Moon
in one and a quarter seconds.

Long-distance travelers who have been round the world some dozen times
have journeyed a greater distance.

The other stars (beginning with the Sun) are incomparably farther from
us. Yet it has been found possible to determine their distances, and
the same method has been employed.

But it will at once be seen that different measures are required in
calculating the distance of the Sun, 388 times farther from us than the
Moon, for from here to the orb of day is 12,000 times the breadth of our
planet. Here we must not think of erecting a triangle with the diameter
of the Earth for its base: the two ideal lines drawn from the
extremities of this diameter would come together between the Earth and
the Sun; there would be no triangle, and the measurement would be
absurd.

In order to measure the distance which separates the Ea