Then came a period of scanty rainfall lasting till about 1896. Thus the climate and the crops completed a cycle. Dry conditions returned. just as the summer returns in the shorter cycle of the year. Year after year the rainfall was scanty and the crops were poor. The farmers were able to struggle along only by mortgaging their houses and getting more and more into debt. At last, with no improvement in rainfall, conditions became so bad that farms were abandoned by the hundred. Many families were too poor to pay railroad fares. They packed up all their belongings in great farm wagons:and drove away seeking new homes. During this low period in the cycle of rainfall not only did the farmers themselves suffer, but the merchants who supplied their wants, the people back in the East who had loaned them money, the manufacturers who made the goods that they con sumed, and the railroads that usually carried the crops that they raised.
How Dry Farming Helps in Regions of Scanty Rainfall.—Little by little the farmers of dry regions are learning to provide against drought. In Kansas, for example, during the comparatively favor able period since the nineties they have learned to preserve the water in the soil for many months or even from one year to another. They do this by plowing or harrowing after every rain in order to break up the crust that forms when the soil dries. Thus the surface is always Covered with a layer of soft, dry dust. Anyone who has made bread knows how flour, which is merely wheat dust, almost refuses to allow the water to enter it except by the aid of vigorous stirring. Such a layer of dust on the surface of the fields prevents the ground water from evaporating and hence is a great help to the crops. This method of "dry farming" enables crops to be grown with compar atively little rainfall. It is a great help to the farmer, but demands a large amount of labor. Even where dry-farming is practiced, how ever, it is only a partial remedy for scanty rainfall. Abundant rain fall still causes prosperity, while scanty rainfall may bring poverty.
Variations in Rainfall and Migration from Western Europe.— One of the most important occurrences of the past hundred years has been the migration of Europeans from the Old World to the New. The fundamental cause is of course the fact that America is a new land with abundant opportunities, while Europe is an old land densely populated. These conditions are a constant cause of migration, and if acting alone would give a rise to a steady flow of people into the United States. Other variable factors, however, enter into the prob
lem from year to year. From 1914 to 1920 the Great War was the chief factor in controlling migration, but under ordinary conditions changes in rainfall or climatic cycles are the chief cause of variation. Too much rainfall in Scandinavia, Britain, the Netherlands, and Germany may be as bad as too little hi Kansas. Those countries are so far north and are usually so well supplied with rain that when the rainfall is above the average, vegetation does not get enough sun and warmth. Hence the crops are scanty; poverty and discontent arise; people want to get away to another country; and there is much emigration. The United States lies enough farther south than north western Europe so that on the whole it is benefited by abundant rainfall. Hence prosperity is apt to prevail here when poverty pre vails there, provided the rainfall cycles are the same in the two places, which is often the case. Thus good conditions here may attract people from Europe just when poor conditions there are driving them away.
How too Much Rain Brings the Irish to America.—The European region that has been most affected by emigration to America is Ire land. Through emigration the population of that country has been reduced by half. At the census of 1841 there were 8,200,000 people, and in 1911 only 4,400,000. As in many other cases the emigration from Ireland is due to a constant cause which is within human control, and a variable geographical cause which is beyond human control. The constant cause is the unfavorable social conditions. For instance, the land has till recently been largely owned by a few absentee land lords who did not often visit their estates and who cared little for the poor tenants provided the rent was paid. The variable cause is the fluctuations in the rainfall, and hence in the potato crop, the chief agricultural resource of Ireland.
Previous to about 1845 Ireland enjoyed a comparatively dry period with excellent crops most of the time. The population in creased until in 1845 it reached a maximum of 8,300,000. Then came a series of damp years with such complete failure of the potato crop, that 200,000 to 300,000 people died of starvation and fever. The British government provided work for over 700,000 people at one time, but this was not enough. Then food was distributed in enor mous quantities, and over 3,000,000 people were at one period supplied with rations. Nevertheless such great discontent arose that in 1848 a rebellion was attempted.