100 | 4.3 | 13.5 | 32.0 | 34.0 | 34.0 | 34.0 | 34.0
1,000 | 4.3 | 13.5 | 42.9 | 101.8 | 107.5 | 107.5 | 107.5
10,000 | 4.3 | 13.5 | 42.9 | 135.7 | 320.3 | 340.0 | 340.3
100,000 | 4.3 | 13.5 | 42.9 | 135.7 | 429.3 | 1013.0 | 1075.3
---------+-----+------+-------+--------+---------+----------+----------

[Footnote 1: As an example, this table shows that waves 1,000 feet
in length travel 43 nautical miles per hour in water 1,000 feet
deep. The length is measured from crest to crest.]

From these numbers it appears that--

1. When the length of the wave is not greater than the depth of the
water, the velocity of the wave depends (sensibly) only on its length,
and is proportional to the square root of its length.

2. When the length of the wave is not less than a thousand times the
depth of the water, the velocity of the wave depends (sensibly) only
on the depth, and is proportional to the square root of the depth.

It is, in fact, the same as the velocity which a free body would
acquire by falling from rest under the action of gravity through a
height equal to half the depth of the water.

_Rollers_ are of the nature of a violent _ground swell_, and possibly
the worst of them may be due to the propagation of an earthquake wave.
They come with little notice, and rarely last long. All the small
islands in the Mid-Atlantic experience them, and they are frequent on
the African coast in the calm season. They are also not unknown in the
other oceans. In discussing the meteorology of the equatorial district