WAGES NOT UNIFORM — NON-COMPETING GROUPS 59

Southern States the utilization of a low-lying stratum of “poor
whites” (not to mention the negroes) operated in the same way.
The effect was to give an advantage to those industries, or those
ways of conducting industries, in which the low-lying group of
labor was used in large proportion. Industries of this type were
accordingly in the same position in regard to international trade
as if they had a comparative advantage; or if not so much as
this, something to offset a lack of such advantage.
In the iron industry — that is, in the making of crude and halffinished
 iron and steel — the effect was of the former sort: the
situation served to give a comparative advantage. The industry
uses great masses of labor. The industry grew in the United
States at an extraordinary pace between 1890 and 1915, and came
to be an important industry of export. Here, too, the labor factor
was not the only one; but it was an important one. It contributed
 to the remarkable overturn by which the United States,
formerly an importer of iron and steel, became a great exporter of
them.
In the textile industries an analogous development took place,
but here not so much in the way of greater exports as of less
imports; not so much the attainment of a clear comparative
advantage as the elimination, in part or in whole, of a lack of
superiority. The shift for the purposes of international trade was
negative rather than positive. Those textile industries which
could use unskilled labor for tending semi-automatic machinery
for mass production found a plentiful and cheap supply at their
command. Those for which still other conditions also were
favorable, notably those manufacturing the cheap and medium
grades of cotton fabrics, grew apace. Their position of indifference
 to foreign competition, almost if not quite attained even
under the earlier conditions, was strengthened and consolidated
by the cheapness of the routine labor. Textile industries of a
different type, such as the silk and worsted manufactures, were
enabled to attain a half-way position. For them the general
conditions were less favorable; in order to hold their own against
foreign competition, they needed a tariff prop much more than