Some writers endeavor to justify, under our constitutions, the regulation of rates by the principle of eminent domain; but this source seems far-fetched and unnecessary. It is, of course, done under the police power; but the precedent for that use of the police power is to be found in the history of English law and statutes. Thus we have noted in the Statute of Westminster I, A.D. 1275, that excessive toll contrary to the common custom of the realm was forbidden in market towns. The very phraseology of this statute indicates the antiquity of the doctrine that tolls must be reasonable; but "toll" was always a technical term, not for ordinary prices of commodities, but for a use or service which was in some way dependent upon law or ordinance. In the very opinion of Chief Justice Waite, he quotes Lord Hale, saying that the king "has a right of franchise or privilege, that no man may set up a common ferry without a prescription time out of mind, or a charter from the king," and so later he quotes Lord Hale as saying that the same principle applies to a public wharf "because they are the wharves only licensed by the king." We also found legislation fixing rents and so on in staple towns, and consequently of the charges of property owners therein, such towns having grant of a special privilege. The early law books are full of cases showing that discrimination and extortion were unlawful, even criminal, offences. And finally, as Chief Justice Waite points out, we find the rates of carriers fixed by law in 1691. Ordinary carriers, not having the right of eminent domain such as express companies, might to-day be considered to have no legal monopoly, and indeed, possibly for that reason, the regulation of charges of express companies has not yet been attempted; but in King William's time it was doubtless considered that the carriers had special privileges on the highways, as indeed they did.