of Mexico and have twice destroyed Florida’s orange groves within a decade.  Mountain ranges are conspicuous in political geography because they are the natural boundary between many nations and languages, as the Pyrenees between France and Spain, the Alps between Austria and Italy, and the Himalayas between Tibet and India.  Mountains sometimes guard nations from attack by the isolation they give, and therefore promote national unity.  Thus the Swiss are among the few peoples in Europe who have maintained the integrity of their state.  Commercially, mountains are of great importance as a source of water, 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 debris 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. 
 II.  Political geography. 
        Why? 
        Where?
         a, b, etc. 
III.  Commerce. 
        Why? 
        Where?
         a, b, etc.

B. Make an outline of the following paragraph:—­

1.  The armor of the different classes was also accurately ordered by the law.  The first class was ordered to wear for the defense of the body, brazen helmets, shields, and coats of mail, and to bear spears and swords, excepting the mechanics, who were to carry the necessary military engines and to serve without arms.  The members of the second class, excepting that they had bucklers instead of shields and wore no coats of mail, were permitted to bear the same armor and to carry the sword and spear.  The third class had the same armor as the second, excepting that they could not wear greaves for the protection of their legs.  The fourth had no arms excepting a spear and a long javelin.  The fifth merely carried slings and stones for use in them.  To this class belonged the trumpeters and horn blowers.