This, as was shown in Chapter IV (Communication), is the connecting medium of society, and any change in the mechanism by which it is carried on involves a change in society itself. When written records came to tell one generation exactly what its predecessors decreed, the range of social heredity was enlarged and stable institutions arose. When printing came to diffuse knowledge among the many, then the reading public became extensive and powerful; universal education and popular government became possible. With the advent of facilities for rapid transportation and communication, every kind of institution forthwith became organized on a large scale. The Western Union Telegraph Company reached the Pacific Coast in 1861, and soon after acquired control of lines in every part of the United States; in the telegraph business that company itself became the first example of the kind of organization which the facilities it offered to the public made possible in other lines of activity; it was the first trust. The United States Steel Corporation would not be possible without communication by electricity. Even the ship at sea is no longer isolated, but may be reached at any time by orders from land.

The automobile has brought new relations to the well-to-do; it has also brought a new type of criminal. The motion picture has given a new kind of recreation, organized on a large scale hitherto unknown. It has displayed the operations of the underworld before millions of children. The large-scale organization is now being developed to make the motion picture an instrument of instruction as well; only a certain development of the educational machinery is necessary to display whatever we wish to the view of all the children of the state. The phonograph has done the same for sound; proper organization can bring the voice that all want to hear to the ears of all, and for all future time. The solitary student of French can hear a master pronounce it. A club of music lovers in an Iowa village can hear Caruso or a symphony orchestra. What is needed above everything else to-day is the enlistment of sound judgment, correct taste, and the broadest possible human sympathy to select the best for every purpose; then also a nationwide cooperation of every kind of social center - church, school, public hall, club, theater, - to take the best and diffuse it by these new mechanisms to the people who are ready to use it.

One of Ross's classes of stimuli is "contact and cross-fertilization of cultures," which is a variety of agglomeration. The extent to which the members of one group come in contact with those of another depends first of all on just these mechanical facilities for communication, and after that on the growth of the habit of such contact into the forms of social organization. A century ago only a few diplomats, merchants, travelers, and immigrants had direct communication with a foreign nationality; now they are counted by the million. Formerly it was only through persons like these that current literature could be secured from a foreign country. Now (war conditions excepted) a student in a Missouri village can get a book or paper from England as easily as he can from St. Louis, without appreciable difference in expense or great difference in time. The transformation of the world which has come in the last hundred years may be ascribed to the quickening influence of this contact with the unlike - as far as anything so extensive may be ascribed to a single factor. On the other hand, wherever social inertia has been found, it has nearly always been ascribed to lack of communication with the outside world.