tity by which the Moon deviates from
the straight line she would pursue if the Earth were not influencing
her.

The reasoning just stated for the Moon is equally applicable to the Sun.

The distance of the Sun is 23,386 times the radius of the Earth. In
order to know how much the intensity of terrestrial weight would be
diminished at such a distance, we should look, in the first place, for
the square of the number representing the distance--that is, 23,386
multiplied by itself, = 546,905,000. If we divide 4.90 meters, which
represents the attractive force of our planet, by this number, we get
9/1000000 of a millimeter, and we see that at the distance of the Sun,
the Earth's attraction would really be almost _nil_.

Now let us do for our planet what we did for its satellite. Let us trace
the annual orbit of the terrestrial globe round the central orb, and we
shall find that the Earth falls in each second 2.9 millimeters toward
the Sun.

This proportion gives the attractive force of the Sun in relation to
that of the Earth, and proves that the Sun is 324,000 times more
powerful than our world, for 2.9 millimeters divided by 0.000,009 equals
324,000, if worked out into the ultimate fractions neglected here for
the sake of simplicity.

A great number of stars have been weighed by the same method.

Their mass is estimated by the movement of a satellite round them, and
it is by this method that we are able to affirm that Jupiter is 310
times heavier than the Earth, Saturn 92 times, Neptune 16 times, Uranus
14 times, while Mars is much less heavy, its weight being only
two-thirds that of our own.

The planets which have no satellites have been weighed by the
perturbations which they cause in other stars, or in the imprudent
comets that sometimes tarry in their vicinity. Mercury weighs very much
less than the Earth (only 6/100) and Venus about 8/10. So the beautiful
star of the evening and morning is not so light as her name might imply,
and there is no great difference between her weight and our own.

As the Moon has no secondary body submitted to her influence, her weight
has been calculated by reckoning the amount of water she attracts at
each tide in the ocean, or by observing the effects of her attraction on
the terrestrial globe. When the Moon is before us, in the last quarter,
she makes us travel faster, whereas in the first quarter, when she is
behind, she delays us.

All the calculations agree in showing us