in each case and to convey in no instance any false impression of exactitude. The greatest possibilities of error are usually in the less important details and errors of this kind seldom can be great enough to vitiate seriously the totals arrived at. Whenever possible, the major conclusions have been verified by independent methods and from different sources of information. The closeness with which most of these independent estimates have checked has frequently been both surprising and gratifying.
The general sources of information and methods of procedure have usually been indicated either in the text or in a footnote. It has seemed unwise to attempt to trace in full all the methods used, for they have been so diverse and involved that their description in detail would require several volumes as large as this one. Neither has any attempt been made to give exact page references to all reports used. Figures have been taken from dozens or even hundreds of places in many of the sources cited, and to state the origin of each number would be to make the work so cumbersome as to discourage the average reader. This study is intended to give an impressionistic picture of the subject under consideration and to convey a correct idea as to the general supply and distribution of wealth and income. While no little effort has been expended in estimating and reestimating, checking and rechecking with a view to
