CHAPTER I
Introduction

From time to time attention has been drawn by econom¬
ists and sociologists to the world-wide movement of popu¬
lation from the country to the cities. This concentration
of population and the growth of cities should be carefully
distinguished from the increasing intensity or congestion of
population in certain sections of large urban areas. The
former phenomenon is universal in this country and abroad,
the latter is confined to a few of the principal cities. As
concentration of population in cities was one of the leading
social phenomena of the nineteenth, so congestion bids fair
to underlie the most critical social problems of the twentieth
century.

The present essay will not attempt, beyond the briefest
summary, to deal with the causes or status of the move¬
ment of population from the country into the cities. Nor
will it attempt to make a complete study of the problem of
congestion. It will seek merely to isolate, to analyze and
to investigate some of the factors which have made for the
very great density of population in New York City. That
city is without doubt the most extreme example of conges¬
tion, and as a laboratory for research it is unequaled. The
specific set of factors or causes of congestion which will be
dealt with in the following pages are industrial. The
writer recognizes other economic causes, and still other
causes which may be called social. These are important,
they are not to be underestimated, but they lie without the

.     91                                                                                           9