In a little over one hundred years, those working by the light of science have found the true philosopher’s stone in modern chemistry. The value of only a part of these new products exceeds the nominal value of all the gold in the world. The value of our mechanical and chemical products is great, but it is surpassed by that of food products. If these did not keep pace with the increase of population, the theories of Malthus would be true—but he never saw a modern reaper. The steam-plough was invented in England some fifty years since, but the great use of agricultural machinery dates from our Civil War, when so many men were taken from agriculture. It became necessary to fill their places with machinery. Without tracing the steps which have led to it, we may say that the common type is what is called “the binder,” and is a machine drawn chiefly by animals, and in some cases by a field locomotive. It cuts, rakes, and binds sheaves of grain at one operation. Sometimes threshing and winnowing machines are combined with it, and the grain is delivered into bags ready for the market. Different machines are used for cutting and binding corn, and for mowing and raking hay, but the most important of all is the grain-binder. The extent of their use may be known from the fact that 75,000 tons of twine are used by these machines annually. It is estimated that there are in the United States 1,500,000 of these machines, but as the harvest is earlier in the South, there are probably not over 1,000,000 in use at one time. As each machine takes the place of sixteen men, this means that 16,000,000 men are released from farming for other pursuits. The “man with the hoe” has disappeared from the real world, and is only to be found in the dreams of poets. It is fair to assume that a large part of these 16,000,000 men have gone into manufacturing, the operating of railways, and other pursuits. The use of agricultural machinery, therefore, is one explanation of why the United States produces eight-tenths of the world’s cotton and corn, one-quarter of its wheat, one-third of its meat and iron, two-fifths of its steel, and one-third of its coal, and a large part of the world’s manufactured goods. CONCLUSION It is a very interesting question, why was this great development of material prosperity delayed so late? Why did it wait until the nineteenth century, and then all at once increase with such rapid strides? It was not until modern times that the reign of law was greatly extended, and men were insured the product of their labors. Then came the union of scientists, inventors, and engineers. So long as these three classes worked separately but little was done. There was an antagonism between them. Ancient writers went so far as to say that the invention of the arch and of the potter’s wheel were beneath the dignity of a philosopher.