The climate of North America south of the divide which separates the streams flowing toward the Arctic Circle from those entering the Atlantic south of Labrador may be said to resemble that of Europe in all important respects. The winters are far colder; but the summer seasons, which determine the usefulness of the soil to man, are as warm and quickening to plants as are those of the Old World. The more considerable cold of winter is a disadvantage, inasmuch as it limits the work of agriculture to a smaller part of the year, and requires a greater expense in the keeping of livestock. This is a considerable evil, especially in the regions north of the parallel of forty degrees; but the cold is not greater than in Northern Germany or in Scotland. There can be no doubt that the body and the mind receive certain advantages from the tonic quality of the winters which compensate for this loss. Nearly the whole of North America that is within the limits of the United States receives some share of frost. This secures it against the permanent occupation of contagious fevers, which from time to time find their way to it from the tropics. North America, east of the 100th meridian (west of Greenwich) and north of thirty-five degrees, has a soil which is on the whole superior to that of Europe. Practically the whole of this vast area is tillable, and the variety of crops is very great, considerably greater than that of Europe. West of the 100th meridian the rainfall diminishes rapidly, being especially limited in the summer season. The winters become longer and more extreme throughout all the region within or under the climatic influence of the Cordilleras; the soil is thinner, and over vast regions almost wanting. In certain exceptional tracts as far westward as the Saskatchewan, and at points along the line between the United States and Canada to the south of that valley, there are considerable areas of good soil; but, considered in a general way, we may exclude all the region between the 100th meridian and the Sierra Nevada range from the hope of any great agricultural future. Even should the rainfall be increased by tree-planting in those regions where trees may grow, the quality of the soil in this district, even where soil exists, is often too poor for any use. Yet in some parts it is very good, and if tree-planting should increase the rainfall, some limited areas will be tillable.