The foregoing illustrates the movement of the exchanges constantly proceeding ... between ... different communities.... There is a network of relationship between banks through which each local community and market is connected with all other communities and markets.... No locality is so remote as to be outside of the circle and no community's sales and purchases are so scattered but that they can be brought together in the settlements. Each bank is the center of a circle of which it is the clearing agent; all payments between its own customers may be made by a transfer of credit upon its books. If there are two banks or more banks in a town, all payments between their customers are resolved into offsets between these banks, and in like manner all payments between localities are resolved into offsets between banks, and if not settled in local centers are passed up to larger and larger clearing centers.... But while the cross-payments of trade may be depended upon in the long run to balance and settle themselves, it does not follow that they will do so from day to day, or that they coincide so closely that payments in money are never required. An individual's sales and purchases are seldom made at the same time, and the sales and purchases of communities are not constantly balanced. The trade of a one-crop farming district will not be so evenly balanced as one of a district in which mixed farming prevails, and in every industry there are periods, usually recurring every year, when the payments exceed the current income, and corresponding periods when income exceeds outgo.... A region like the cotton states, whose products move quickly to market, may have large credit balances at one season and at another be wanting to borrow.... The banker is an equalizing agency in the situation. He stands in the breach: he must either supply the missing offsets of credit, or, as a last resort, make the payments in money.... The entire system of settlements, with transfers and offsets and advances and interchange of capital and credit, is exceedingly interesting and wonderfully simple and effective, but depends for its effectiveness upon a scrupulous observance of the principle upon which it is based. That principle is the natural reciprocity of trade.... While there are balances from time to time in the exchanges ... between different localities ... which cannot be settled without shipments of money, they are usually met without inconvenience unless there is a disturbance of credit. EXCHANGE RELATIONS BETWEEN CHICAGO AND NEW YORK [97]... It should always be borne in mind that the fact that New York City is the country's dominating financial market results in making New York funds acceptable everywhere as a means of payment, and in making a ready market for New York exchange throughout the country for a large part of the year.