used in the construction of buildings
It's obvious from the passage that the widespread epidemics in Europe in the Middle Ages. were believed to be the result of bad luck
67 WHY LEAVE? If people are satisfied where they are, they will not migrate. Throughout history, people have left their native lands for a variety of reasons: religious or racial persecution, lack of political freedom, economic deprivation. The forces that attracted them to new homelands were the opposites of these: religious and political freedom, ethnic tolerance, economic opportunity. The leading motive behind migration has always been economic. Overpopulation creates shortages of jobs and food. The natural resources of a region can become exhausted, impelling a whole group of people to migrate. People who are oppressed for any reason will in all likelihood be economically deprived as well. The movement from farm to city is a prime example of migration for economic reasons. During the Industrial Revolution of the 18th and 19th centuries, millions of people left poverty-stricken rural areas for the cities. Even the low-paying, seven-day-a-week jobs in early factories were better than the endless toil and misery of trying to earn a living on the farm. This search for jobs in urban areas has continued to be a leading cause of migration up to the present.