It seems to me, therefore, that the real reason, both logical and historical, for regulation of rates rests on the fact that the person or corporation so regulated is given a monopoly or franchise by some law or ordinance, or at least a special privilege from the State; or at least that he maintains a wharf, a bridge, or a ferry, or other avocation which (really for the same reason) has, from time immemorial, been subject to such regulation.  This, indeed, has been the doctrine officially adopted by the Commonwealth of Massachusetts in its legislation—­“Where monopoly is permitted, State regulation is necessary.”  The new “Business” Corporation Act of 1903 makes the express distinction between public-service corporations and all other private corporations for gain:  it applies to “all corporations ... established for the purpose of carrying on business for profit ... but not to ... railroad or street railway company, telegraph or telephone company, gas or electric light, heat or power company, canal, aqueduct or water company, cemetery or crematory company, or to any other corporations which now have or may hereafter have the right to take or condemn land or to exercise franchises in public ways granted by the commonwealth or by any county, city, or town.”  The implication is that such other corporations are not given the entire freedom of action and contract conferred by this Business Corporation Act.  Where the State creates a monopoly, it puts the public at the mercy of the grantee of that franchise.  Therefore, it is logical and just that it should regulate the rates.  The test, however, is not and cannot be, that the man is ready to serve all comers, or even that he is compelled so to do; hotel-keepers, barbers, restaurants, doctors, etc., have never had their charges regulated by law.  In early days most tradesmen were compelled to serve any and all, at an equal price, under liability for damages.[1] Mills, indeed, have always been subject to have their tolls regulated; at least, a certain proportion of the grist had to go to the miller; but even if it be held they had no peculiar franchise, the exception is as old as the rule.

[Footnote 1:  Holmes J., ex banco, in United States v.  Standard Oil Co., March 14, 1910.]

It is further noteworthy that since the Granger cases themselves, there has been no extension of the doctrine of Chief Justice Waite to other trades or industries, while the extent of the doctrine, that is, the amount of regulation permissible under the Constitution, has been very much limited.  Waite’s opinion gives no intimation of any constitutional limit whatever, but dozens of the decisions of the Supreme Court since draw the limit this side of the point of confiscation; that is to say, at a “reasonable return,” whatever that phrase may mean.  It was, indeed, at first extended to semi-private grain elevators on the prairies, to elevators monopolizing the water front of Buffalo, New York, and to floating elevators