above the sea-level. The humidity of the climate is, as a rule, great in proportion to the quantity of water in its neighborhood, and to the height of its temperature; although, for instance, in Europe, the number of rainy days increases, the further we advance towards the north. Although the distance of a place from the equator and its height above the level of the sea have, in many respects, a similar effect (vertical, horizontal isothermal lines and zones of production), mountainous regions are uniformly distinguished by a greater degree of humidity, which makes them better adapted for pasturage and forest-culture. But the flora of a locality, being the resultant of all its conditions, affords us a much better criterion of the value of the climate for economic purposes, than the most accurate thermometric observations. Other things being equal, the productive force of nature operates, doubtless, with most energy, in warm climates. The more remote a country is from the equator, the more is its fertility confined to its lowest parts. Greater heat will, as a rule, ripen the same product sooner, and thus permit the same land to be used several times in the same year. Each individual

5 Hence it is that the isothermal lines are not parallel with the equator or with one another. The greater number of these have two northern and two southern summits; the former on the western coasts of Europe and America, and the letter in eastern North America, and in the interior of Asia.

The quantity of rain which falls every year is, at St. Petersburg and Pesth, from 16 to 17 inches; at Berlin 19, Mannheim 21, Tübingen 26: in the interior of France 16-24; on the French coast 25, on the eastern coast of England 24, on the western coast 35, in Milan 36, Genoa 44, on the coast of most tropical lands 70-120. On the political-economical influences of most climates, see Gobbi, Ueber die Abhängikeit der Populationskräfte von den einfachen Grundfstoffen, 1842.

The snow limit at Mageröe in Norway is 2,200, in Iceland 2,900, in the northern Ural 4,500, in the Alps 8,200, in the Caucasus 10,400, and Quito 14,850 feet high. Hence it is that mountainous countries which produce nothing in the north, make magnificent vineyards in warmer countries.

8 In central Germany, even a second crop can be produced after the corn harvest. In Arabia, the same seed produces three harvests, because the grain which falls at the time of harvesting to the ground, germinates immediately and suffices for new seed. (Niebuhr, Beschreibung, 154.)

10

harvest, as a rule, is more abundant,' and the products better in many respects. The fruit, for instance, and wine, contain more sugar, and oleaginous plants contain more oil. Lastly, since nature in warm countries is so much more generous, it may be utilized by man with less regard for consequences. There is less need of extensive woods, of large winter supplies, especially for animals; "1 fewer buildings are demanded, and there is also less demand for human and brute labor, since the work of plowing, sowing etc., extends over a greater portion of the year.12 It is true, on the other hand, that also the

9 Thus in the northern states of the American union, wheat yields a return of only from four to five times the amount sown; in France, 5-6 times (Lavoisier): in Chili, 12 times; in northern Mexico, 17 times; in Peru, 18 and 20 times; in southern Mexico, 25 and even 35 times; in Germany, maize seed yields at best one hundred fold, while in the torrid zone there is a return of from three hundred to four hundred fold, generally.

1o Andalusian corn produces in the mill only one-half as much bran-waste as Baltic wheat produces. Bourgoing, Tableau de l'Espagne, II, 155. Baltic wheat contains 6-7 per cent. of azote, and Algerian, 20-25 per cent. (Kabsch, Pflanzenleben der Erde, 1865.)

11 In Europe the blossoming season is retarded four days for each degree of northern latitude. (Schübler.) As we advance towards the north, the difference becomes less noticeable, but more so as we go towards the south. In mountainous countries a similar difference is observable, produced by a like climatic influence. It is from about 10 to 12 days, for a heighth of from 500 to 600 feet. (Wolff, Naturgesetzliche Grundlagen des Ackerbaues I, p. 332 ff.) In the cantons, in which the Swiss confederation had its origin, the pasturage of the Alps lasts generally thirteen weeks, but in the higher Alps it lasts only from six to seven weeks. (Businger, C. Unterwalden, p. 52.)

12 In central Italy, winter wheat may be sown in October, November or December; summer wheat, in February or March. (Sismondi, Tableau de l'Agriculture Toscane, p. 35.) In Judæa, it was possible to harvest figs ten months in the year. (Joseph, Bell. Jud., III, p. 10.) On the other hand, there is Jemtland, where the peasant in many places surrounds the northern portion of his cornfield with fagots, and lights them in August when the north wind blows, to protect his land from the frost; and where the expression "green years" is used to designate those in which the harvest has to be reaped before it is ripe. (Forsell, Statistik von Schweden, 24.) In the valuation made of the lands of the kingdom of Saxony, for assessment purposes, the cost of supporting a yoke of oxen in the lowest country is estimated at only three-fourths of what it is in the highest localities, because in the former, 200 work days can be calculated upon in the year, in the latter only 159.

destructive force of nature is greater in warmer than in colder countries. (§ 209.)13

SECTION XXXIII.

EXTERNAL NATURE.-GIFTS OF NATURE WITH VALUE IN EXCHANGE.

B. Those gifts of external nature which may become objects of private property, and at the same time possess sufficient relative scarcity to give them value in exchange, are either movable, and exhaustible in a given place, or firmly connected with the land. The first category embraces, for instance, such wild animals and plants as serve some useful purpose, minerals, above all, fossil combustible matter1-the

In central Russia, the greater part of the labor of agriculture, sowing and harvesting, has to be finished within the space of four months. In central Germany, they are spread over seven months. Other things being equal, seven horses and ploughmen are needed in Russia where only four are called for in central Germany. (von Haxthausen, Studien I, 174.) On the impediments put in the way of agriculture by the climate of eastern Prussia, see Meitzen, Boden und landwirthsch. Verhältnisse des preussichen Staats, 1868, I, Abschn., 6.

13" In both hemispheres, the zone in which the temperature decreases most rapidly lies between the 40th and 50th degrees of north latitude. This circumstance must have a happy influence on the culture and industry of the nation inhabiting the neighborhood of that zone. Here is the point where the regions of the vine touch upon those of the olive. Nowhere in the world, do the products of the vegetable kingdom, and the most varied wonders of agriculture, follow with such rapidity on one another. The great variety of products enlivens the commerce and increases the industrial activity of agricultural nations." (Humboldt.) It is truc, however, that tropical countries possess, also, in their mountainous parts, the tierra fria, templada and caliente, superimposed the one on the other.

1 The aggregate coal supply of Great Britain (1869) was 2,180 millions cwt.; of Belgium (1862), 207 millions; of France (1868) 256 millions; of Prussia (1870), 600 millions, of Austria (1870), including brown lignite coal, 158 millions; of Russia (1868), only a little over 9 millions. The great English coal field, in the counties of Durham and Northumberland, embraces 732 English square miles; that of South Wales, 1,200, with a depth of 95 feet, so that the geographical square mile contains here 679 millions of tons, each of twenty

"black diamonds," coal, of which, with its canals, Franklin said that it had made England what it is. The economical effect of their moveable character is best seen, when the use made of an ordinary stratum of coal is compared with that of a protracted subterranean fire in a coal mine. The latter can be directly useful only to those in its immediate vicinity. Every lower layer of the burning coal would be less useful. An increase of its actual power by accumulation in time or place is scarcely possible. In all these respects, the movable coal is incomparably better adapted to the satisfaction of man's wants. It may be said that the capacity of heat for drying, distilling, melting and hardening purposes, of imparting rapid motion to heavy objects by the production of confined steam, is, at least, a thousand times as great when a thousand bushels of coal are consumed as when one is consumed. In most cases even the concentration of a large quantity of coal will increase, the result not only absolutely, but relatively. 3 4

cwt. To obtain the same quantity of combustible material as was furnished to Prussia, in 1865, by its coal, it would be necessary to use up 6,331 square miles of forest. (von Dechen, in Engel's Zeitschrift, 1867, 258.) The supply of coal is, of course, exhaustible while, for instance, turf-fields replace themselves by slow degrees. Compare Griesbach, über die Bildung des Torfs, in the Göttinger Studien, 1845, vol. I. The importance of the coal-fields of the United States, which are twenty-two times as large as those of Great Britain, in the distant future, cannot be over-estimated.

I need only call attention to the earth-fire (Erdbrand) for the purpose of forcing the growth of garden plants in the neighborhood of Zwickau, which is said to have existed since 1505.

Thus, in Watt's steam engines of the larger kind, an hourly consumption of ten pounds of coal is needed to produce a force equivalent to that of one horse, while in the smallest machines of only one horse power, twenty-two pounds are needed. See Prechtl, Technolo. Encyklopädie, III, 669.

It is easy to see that it is the most important substances needed in industry which are mentioned in this section. Many political economists have considered the principal difference between agriculture and the industries and economies of towns to lie in the contrast here referred to. Thus, A. Serra, Sulle Cause che possono far abbondare li Regni d'oro e d'argento, dove non sono miniere, 1613, I, 3. See the description of the difference between land and machines in Malthus, Principles, III, 5; Senior, Outlines, 86. But it is nothing more than a difference of gradation. Even in the most

SECTION XXXIV.

EXTERNAL NATURE.

(CONTINUED.)

The materials, forces and relations or conditions of external nature, immovably connected with parts of the land, even when in themselves exhaustless, either allow only of a definite amount of economic utilization, as, for instance, the mechanical force of a given waterfall, which can drive only a definite number of mills of a definite size;1 or their increased utilization is accompanied by difficulties which increase with still greater rapidity. This last is the case, especially in the employment of land for agricultural purposes. It is, according to Senior, one of the four fundamental axioms of Political Economy, that additional labor, spent on a given quantity of land, produces, as a rule, a relatively smaller yield; assuming, of course, that the art of agriculture remains the same.1 It is not possible to

active of businesses there is a limit which the accumulation of means of production cannot pass without a relative diminution of the income. This boundary is imposed by the limited nature of those organic beings which must contribute to production either actively or passively. Thus, for instance, a manufacturing establishment or commercial business can be enlarged with advantage only so long as it is still possible for one superintendent to conduct it. And so, when cattle are furnished with very abundant and substantial food, a pound of meat costs the producer a much higher price than when they are more moderately supplied: sometimes in the ratio of 1.95: 0.98. Boussingault, Economie rurale, II. Where there is absolute over-feeding, the producer must suffer loss. But, even inorganic nature imposes its own limits here; as, for instance, when ships, machines etc., on account of the insufficient strength of the materials of which they are made, cannot be constructed beyond a certain size. But all these limits are much narrower than those imposed by the quality of immovability.

1 Senior, Outlines, 26, 81 ff. See Stewart, Principles, II, ch. 11; Ortes, E. N., I, 18, II, 18 ff. This most important principle in Political Economy is thus illustrated by John Stuart Mill, Principles, book I, ch. 12. "The limitation to production from the properties of the soil is not like the obstacle opposed by a wall, which stands immovable in one particular spot, and offers no hindrance to motion short of stopping it entirely. We may rather compare it to a highly elastic and extendible band, which is hardly ever so vio