The logic of the matter is quite plain in the light of biologic evolution. Movement is necessary to the existence of animals. The animal, in the order of evolution a higher form of life than the plants, which are more fixed, goes to seek food and in so doing opens up a wider range of choices in life. With few exceptions the only way in which animals can better their economic environment is by moving themselves to a place where goods are more plentiful. In this matter of locomotion the birds have attained the highest point in evolution. Man, while he has by mechanical means greatly added to his own powers of locomotion, has also developed to a very high de gree of perfection his ability to move other things. He trans• ports them to the places where they can best serve his purposes, and by this means he adds enormously to his income. Trans portation is thus one of the earliest and most natural of the ways in which man increases his income, and the elaborate equipment which he has developed for the transportation of goods finds its economic uses in the gratification of human de sires. The subject of transportation, with its various rami fications, furnishes some of the most interesting problems of valuation with which the student of economics has to deal.
§ 3. Relation of time to value. As the days and hours succeed each other in the life of man, they bring with them a constant succession of desires, forming an endless stream as long as life itself endures. To meet and satisfy these desires a corresponding stream of goods is necessary. (See Chapter 3, section 10.) Nature furnishes man with the raw material for this stream of goods, and even to a limited extent provides fruits and other things all ready for direct use. But in com bining and using the agents at his command, man must give much thought and effort to the end that the direct goods may ripen at the particular time when the need for them arises. All desire is related to a particular point of time, and man, in a variety of ways, controls the time at which the uses of goods become available.
One way in which this control is exerted is through the sim ple process of saving goods for future use. If the goods are durable, a present surplus, or even things which answer to strong present desires, may, if the claims of the future make a sufficient appeal, be reserved for use at some later time. Choices of this sort between present and future are constantly being made, and constitute an important aspect of our eco nomic activity. A new machine may be driven twenty thou sand miles in the first year, with a large resulting deprecia tion, and large expense for upkeep. Or its use may with care be extended over a number of years. The gamily may spend its full yearly income, or lay aside something for the future. The business man may work long hours to accumulate a for tune in his early years, or he may take more leisure and en joyment as he goes along.
All the decisions in such cases depend on one's mental atti tude, one's habit of life, toward present and future. Men differ greatly in this respect, ranging all the way from the spendthrift to the miser. At a later point in our study we shall have occasion to inquire more deeply into this matter.
§ 4. Indirect agencies for hastening the uses of goods. Our present concern is with the use of indirect agents for the purpose of controlling the time at which the uses of goods become available. Man contrives agencies both to hasten and to postpone the processes of nature, and thereby makes goods better or worse for his purposes. Greenhouses are built and equipped with heating apparatus in order to produce early vegetables and flowers; incubators and brooders are employed to provide the market with the tender broiler earlier in the season than the mother hen would do it; apparatus for making artificial ice is operated in the summer time in places where ice is sure to be a free good a few months later; southern fruits and vegetables are shipped north by fast freight to places which within a few weeks will have an abundant supply of their own home-grown produce. In all these cases the thing that man is striving to do is to make things available at an earlier point of time. And he employs a very considerable amount of apparatus (indirect agents) to accomplish his end.
Likewise the time of indirect uses may be hastened by the use of other indirect agents (of "lower rank"). The sapling is planted in the forest to hasten the process of nature in grow ing wood to be used in industry ; the drying-kiln makes it pos sible to use the lumber newly cut ; gas and electricity lighting the factory make possible overtime work to fill rush orders; fuel is burnt in the locomotive to bring to the factory the ma terials needed just then. A large part of the transportation by express is to bring machinery and supplies to the factory when urgently needed, and hundreds of dollars have been paid thus for the shipment of a single machine across the conti nent, when a few dollars would have paid the cost of shipment by slower freight.
§ 5. Agencies for postponing the uses of goods. Of as great importance perhaps are the various agencies for keeping goods in proper condition for use at some future time. Grain is regularly kept for months in barns and elevators where it is protected from the weather. Fruit, vegetables, dressed poultry, and other meats are preserved in refrigerators and cold-storage plants, and fruits and vegetables are also kept fresh by chemical means or by being "canned" in jars or other vessels from which germs are excluded. Large stocks of build ing materials and other things not ordinarily spoken of as perishable are nevertheless kept under roof to safeguard them from the elements. In some cases the indirect agent is many steps removed from the final gratification of desires. There are factories employed in making paint, cement, creosote, pitch, tar, roofing, etc.—things destined to be used in turn to make, repair, or preserve structures which shelter stocks of other indirect agents for uses that are still in the more or less dis tant future. There is method, of course, in the whole complex process. The end finally achieved is the production of "di rect" goods at the particular time when they are most desired by men.