which they store in snow, glaciers, and lakes. Snow and ice, melting
slowly on the mountains, are an unfailing source of supply for perennial
rivers, and thus promote navigation. Mountains are the largest source of
water-power, which is more valuable than ever now that electricity is
employed to transmit it to convenient centers for use in the industries. A
large part of the mining machinery in the United States is run by water
power. Switzerland, which has no coal, turns the wheels of its mills with
water. Mountains supply most of the metals and minerals, and are therefore
the scene of the largest mining industry. They are also among the greatest
sources of forest wealth. Though the slopes are not favorable for
agriculture they afford good pasturage, and the débris of the rocks washed
into the valleys and plains by mountain torrents supplies good soil. Thus
the Appalachians have been worn down to a comparatively low level, and the
soil formed from their rock particles is the basis of large husbandry.
The scenic attractions of many mountain regions is a source of large
revenue. The Alps attract crowds of tourists, who spend about twenty
million dollars a year in Switzerland and Austria, and give to many
thousands of persons.

--Adams: _Commercial Geography_.



OUTLINE (to be completed)

Mountain ranges have great influence upon--
I. Climate.
Why?
Where?
_a, b,_ etc.