Unless there is some such collateral growth of skill-demanding industries, the new immigrants bring disaster to many of the working-men they undercut. The expansion of the industry will create some good jobs, but not enough to reabsorb the Americans displaced. Thus in the iron-ore-mines of Minnesota, out of seventy-five men kept busy by one steam-shovel, only thirteen get $2.50 a day or more, and $2.50 is the least that will maintain a family on the American standard. It is plain that the advent of sixty-two cheap immigrants might displace sixty-two Americans or Irish, while the setting up of an additional steam shovel would create only thirteen decent-wage jobs for them. Scarcely any industry can grow fast enough to reabsorb into skilled or semi-skilled positions the displaced workmen. Employers observe a tendency for employment to become more fluctuating and seasonal because of access to an elastic supply of aliens, without family or local attachments, ready to go anywhere or do anything. In certain centers, immigrant laborers form, as it were, visible living pools from which the employer can dip as he needs. Why should he smooth out his work evenly through the year in order to keep a labor force composed of family men with local roots when he can always take on "ginnies" without trouble and drop them without compunction? Railroad shops are coming to hire and to "fire" men as they need them instead of relying on the experienced regular employees. In a concern with 30,000 employees, the rate of change is a hundred per cent. a year, and is increasing! Labor leaders notice that employment is becoming more fluctuating, there are fewer steady jobs, and the proportion of men who are justified in founding a home constantly diminishes. IMMIGRATION AND CRISES The fact that during an acute industrial depression in this country the immigrant stream not only runs low, but the departures may exceed the arrivals (as in the eight months following the 1907 panic, when there was a decrease of 124,124 in our alien population), has been made the foundation for the argument that surplus immigrant labor, by promptly taking itself off when times are bad here, relieves the labor market and hastens the return to normal conditions. It is overlooked that only the prosperous go, leaving upon us the burden of the weak unemployed aliens. Moreover, at the first sign of returning prosperity, a freshet of immigrants starts up, thereby checking sharply the good-times tendency toward higher wages and better working conditions. THE RISE OF SOCIAL PRESSURE