Mountains rise in long and comparatively narrow lines or ridges, the
tops of which are often deeply indented, presenting to the eye the
appearance of a series of peaks detached one from another. As each of
these peaks or distinct elevations is called a mountain and often
receives a separate name, the common designation chain or range of
mountains is naturally applied to the whole.
The top of the ridge, from which the waters descend on opposite sides,
is called the crest; and the notches between the peaks, from which
transverse valleys often stretch like deep furrows down the slopes of
the chain, are called passes.