The advantage of the Temperate Zone is not only its moderate and adequate allowance of heat, but its contrast of seasons.  Beyond the range of a vertical sun, grades of temperature change rapidly from latitude to latitude and from summer to winter.  The seasons bring variety of activities, which sharply react upon one another.  Manufactures were in their origin chiefly winter industries, as they still are in small isolated communities.  The modern factory system flourishes best in cooler parts of the Temperate Zone, where the agricultural demands of the summer, spreading over a shorter period, leave a longer time for winter work, and where that once long winter of the Glacial Period, by the scouring action of the ice cap, has reduced the fertile area of the northern fields.  The factory system is also favored, as Heinrich von Treitschke maintains, by the predominance of cool or cold weather, which facilitates the concentration of numerous workmen in large buildings, and renders possible long labor hours the year round,[1439]—­conditions unthinkable in a warm climate.  The iron and steel industries which have grown up about Birmingham, Alabama, find that the long hot summers and mild winters reduce the efficiency of their skilled labor imported from the North.

[Sidenote:  Effects of length of seasons.]

[Sidenote:  Effect of long winters.]

The length of the seasons is of conspicuous importance.  It determines, for instance, whether a given climate permits continuous field work with summer and winter crops, whether field work is possible at all, and how long it is interrupted by excessive cold.  Buckle maintains that climate not only enervates or invigorates man, but affects also the constancy of his work and his capacity for sustained labor throughout the year.  He considers “that no people living in a very northern latitude have ever possessed that steady and unflinching industry for which the inhabitants of temperate regions are remarkable” and assigns as a reason “that the severity of the weather, and, at some seasons, the deficiency of light, render it impossible for the people to continue their usual out-of-door employments.”  The result of this he finds to be desultory habits of work, which help to make the national character fitful and capricious.  He cites in illustration of his principle the people of the Scandinavian and Iberian peninsulas, whom he finds marked “by a certain instability and fickleness of character,” owing to the fact that in Norway and Sweden agricultural labor experiences long interruptions, due to the severity of the winter and the shortness of the days; in Spain and Portugal owing to the heat and drought of summer.[1440] The extreme continental climate of northern of Russia with its violent contrast of the seasons, its severe and protracted winters, enables Leroy-Beaulieu to make a safer application of this principle to the empire of the Czars, which, unlike Scandinavia, feels no ameliorating effect from