In mountain regions， such as the northern Appalachians and Alps， where travel has been made comparatively easy， caring for the summer tourist has become the most important business. Here the old-fashioned customs have been laid aside and the boarding-housea n d hotel in dustr y has largely supplanted all others. Such mountain r egions have become a playground for the rest of the world， and the bracing air and cool climate are as great revenue producers as are fine farming lands and water powers.
CRIPPL E CREEK.
One of the largest mining camps in the world.
In mountain regions rich in ores， mining naturally becomes the chief industry， and here， if there were any secluded native inhabitants， these have been replaced by the energetic miners from distant places. The deep and remote valleys and mountain sides have become the homes of mining camps and cities. Railroads have been built to these， overcoming almost impassable obstructions， and ore crushing and smelting works supply the places of the mills and factories of the manufacturing cities. When the ore fails， the army of workers moves on， and the city， once thriving and booming， becomes suddenly simply an aggregation of empty dwellings.
208.Effect of Mountains on History. -Not only have mountainsbeen retreats for the vanquished， but they have been barriers against further conquest by the conquerors. It is very difficult for an army to traverse a mountain range. For a long time the Alps hemmed in the power of Rome. One of the greatest exploits of Hannibal and later of Napoleon was the passage of these same mountains.
In our own country the Appalachian Mountains acted for a long time as an impassable barrier to the expansion of the Thirteen Colonies. The trails across them were so long and difficult that it was many years before the fertile plains on their western side became populated. The Mohawk valley opened a comparatively easy route at the north， but the Cumberland trail at the south was long， circuitous and full of places suitable for Indian ambushes.
The little mountain country of Switzerland is a buffer state for the rest of Europe. Afghanistan， rough， mountainous and desert， is a buffer state for Asia.
Mountains are often used as boundaries to countries， as in the case of the Pyrenees between France and Spain and the Carpathian Mountains between Austria-Hungary and Roumania. In early times it was thought sufficient to indicate the crest of the mountains as the boundary line， but soon it was found that what was to be called the crest was so open to controversy that definite lines， accurately determined from point to point， had to be substituted.
Sometimes the determination of what shall be called the crest line has given rise to bitter international disputes， as was the case recently between Chile and Argentina. It may happen that mountain boundaries are so broad and complicated that a little country inserts itself along the boundary of two powerful nations and is able to protect itself from being absorbed by either. The little country of Andorra， containing only 150 square miles， situated in a lofty valley on the southern slope of the Pyrenees， with a population not exceeding 10，000， has remained independent for nearly a thousand years in spite of its powerful neighbors.
Summary. -The high parts of the earth are plateaus and mountains. Some plateaus are dissected by the troughs of rivers that run through them and some are broken by faults. When plateaus are old and worn down they usually show remnants of their former surface in buttes and mesas.
Mountains are elevations higher than hills. Block mountains are formed by breaks in the rock layers of the earth； folded mountains are due to folds caused by lateral pressure. Massive mountains are complex in structure and their causes are various. The peaks of mountains are formed by erosion. Many mountains are found in ranges.
Mountains have a great effect upon climate. The windward side of mountains is usually wet and the leeward side dry. The wind， rain， andsnow cause avalanches， which often do great harm to the plants and animals of the mountains and valleys.
Mountains have also a great effect upon history. Not only do they form excellent boundaries between nations and states， but they offer protection to weak animals which are unable to withstand their stronger neighbors in the unprotected conditions of the plains.
QUESTIONS
Describe the characteristics of a young plateau.
Why do not dissected plateaus attract a dense population？ What are the characteristic features of an old plateau？ Where in the United States are broken plateaus found？ Why are there no lofty old mountains？
How are block mountains formed？ Where are mountains of this kind found？ How are folded mountains formed？ Where is a fine example of such mountains to be seen？
What are the characteristics of massive mountains？
What happens to mountains if they are exposed to erosion for a very long time？ Where in the United States are such mountains found？
What are the causes which produce mountain peaks？
How are earthquakes caused？
What are the principal industries in mountain regions？ How do mountains affect climate？
What influence have mountains had upon plants and animals？ What influence do mountains have upon their human inhabitants？ What has been the effect of mountains upon history？
【中文阅读】
190.早期高原--大面积的水平岩石层有时会抬升到高出海面很高的高度， 并由于之前的侵蚀作用，形成地表极不规则的平原，这样的区域就叫做高原。从 高原向低处下沉的地方都十分陡峭，这些区域一般还有河流，并由于河床落差 很大，水流湍急，河谷被冲刷侵蚀得很深，这一切都根源于高原的地质抬升。
如果这里降雨很少的话，河流也就很少，只有一些陡峭嶙峋的沟壑深谷。 这就让行经穿越这一地点变得非常困难。这些沟谷由于过于狭窄，根本不适合 居住，连修路都很困难，这里的河流又太宽，也不好架桥，因此这一类高地一 般都荒无人烟。
如果这些高地位于炎热地带，由于高海拔导致的凉爽气候则成为它们宜居 的亮点，很受人们青睐。但若它们处于本来就很温和的气候带上的话，表面的 温度就很冷了。