Harlan F. Stone

“ Assuming, for present purposes, that the license of the Power Commission is a federal instrumentality, immune from taxation or other direct interference by the state, it does not follow that the property appellant uses in its power project is clothed with that immunity. The exemption of an instrumentality of one government from taxation by the other must be given such a practical construction as will not unduly impair the taxing power of the one or the appropriate exercise of its functions by the other. ”

“ It has never been thought that the taxation of such property at its enhanced value is in effect taxation of its owner for the property of others. Nor can we say that the present tax, based upon what must be taken to be the fair value of appellant's lands profitably used in the business of developing and selling power, is forbidden because that use would not have been possible without the control which appellant has acquired over navigable waters through the grant of its license. ”

“ The contention urged is that the lands are assessed at a higher value than they were before they were submerged, and higher than farm uplands in the neighborhood, and that, since their use as a part of appellant's power project is rendered possible only by the federal license and by the water in the river, the assessment at the higher value, in effect, involves a forbidden tax on the license, and taxation of appellant for the value of the waters of a navigable stream. ”