UNITED STATES r. MISSISSIPPI * BUM EIVEB BOOM 00, 551 �purposes is a right couimon to ail, subject to be regulated and controlled_ by the federal government; or, in absence of any Buch regulation, by the states, where portions of the river lie wholly within their boundaries. This common right, how- ever, to run legs down a river gives no immunity to individ- uals for injuries committed while using it. �The government of the United States, in the interest of this commercial enterprise, inaugurated a System of public im- provements at the falls of St. Anthony, and annual appro- priations are made in the river and harbor bill by congress, and expended under the direction of the secretary of war. The mode of improvement is eonfided to the discretion of that officer, and whatever system is adopted in furtherance of the object designated is done under the authority of congress. The plan suggested by the engineering officers in charge was regarded suitable for the preservation of the falls of St. Anthony, for which the appropriation was made, and to facil- itate the passage of logs from above the falls to the river below. �These improvements were made to protect this branch of commerce, which, in the opinion of congress, required the pres- ervation of the falls, and whether the expenditure of money appropria ted is judicious, or whether the improvements have proved a benefit to private persons, is of no importance. �The only questions involved in this litigation are — First, ■were the structures lawfuUy erected ? The authority to make these improvements cannot be doubtful. The general control, protection, and improvement of the navigable rivers of the United States, in the interest of commerce, are within the constitutional jurisdiction of congress. Second, are the im- provements threatened with injury or destruction ? It is sub- stantially conceded that the acts complained of, if continued, wiil break up and destroy the apron erected over the falls, and the danger apprehended is of a character which, to guard against,' would require the expenditure of a large sum of money. Such interference with the control assumed by the federal government over this locality cannot be permitted, and the parties threatening the safety of the public structures ����
