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land. I say 'insensibly,' because, in the very uncommon case called avulsion, when the violence of the stream separates a considerable part from one piece of land and joins it to another, but in such manner that it can still be identified, the property of the soil so removed naturally continues vested in its former owner. The civil laws have thus provided against and decided this case, when it happens between individual and individual; they ought to unite equity with the welfare of the state, and the care of preventing litigations.

"In case of doubt, every territory terminating on a river s presumed to have no other boundary than the river itself; because nothing is more natural than to take a river for a boundary, when a settlement is made; and wherever there is a doubt, that is always to be presumed which is most natural and most probable.

"As soon as it is determined that a river constitutes the boundary line between two territories, whether it remains common to the inhabitants on each of its banks, or whether each shares half of it, or, finally, whether it belongs entirely to one of them, their rights, with respect to the river, are in nowise changed by the alluvion. If, therefore, it happens that, by a natural effect of the current, one of the two territories receives an increase, while the river gradually encroaches on the opposite bank, the river still remains the natural boundary of the two territories, and, notwithstanding the progressive changes in its course, each retains over it the same rights which it possessed before; so that, if, for instance, it be divided in the middle between the owners of the opposite banks, that middle, though it changes its place, will continue to be the line of separation between the two neighbors. The one loses, it is true, while the other gains; but nature alone produces this change; she destroys the land of the one, while she forms new land for the other. The case cannot be otherwise determined, since they have taken the river alone for their limits.

"But if, instead of a gradual and progressive change of its bed, the river, by an accident merely natural, turns entirely out of its course and runs into one of the two neighboring

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States, the bed which it has abandoned becomes thenceforward their boundary, and remains the property of the former owner of the river, (sec. 267,) the river itself is, as it were, annihilated in all that part while it is reproduced in its new bed, and there belongs only to the State in which it flows."

The result of these authorities puts it beyond doubt that accretion on an ordinary river would leave the boundary between two States the varying centre of the channel, and that avulsion would establish a fixed boundary, to wit: the centre of the abandoned channel. It is contended, however, that the doctrine of accretion has no application to the Missouri River, on account of the rapid and great changes constantly going on in respect to its banks; but the contrary has already been decided by this court in Jefferis v. Land Company, 134 U. S. 178, 189. A question between individuals, growing out of changes in the very place now in controversy, was then before this court; and in the opinion, after referring to the general rule, it was observed: "It is contended by the defendant that this well settled rule is not applicable to land which borders on the Missouri River, because of the peculiar character of that stream and of the soil through which it flows, the course of the river being tortuous, the current rapid, and the soil a soft, sandy loam, not protected from the action of water either by rocks or the roots of trees; the effect being that the river cuts away its banks, sometimes in a large body, and makes for itself a new course, while the earth thus removed is almost simultaneously deposited elsewhere, and new land is formed almost as rapidly as the former bank was carried away. But it has been held by this court that the general law of accretion is applicable to land on the Mississippi River; and, that being so, although the changes on the Missouri River are greater and more rapid than on the Mississippi, the difference does not constitute such a difference in principle as to render inapplicable to the Missouri River the general rule of law." It is true that that case came here on demurrer to a bill, and it was alleged in the bill that the land was formed by "imperceptible degrees," and that the process of accretion "went on so slowly that it could not be observed in its pro

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gress; but, at intervals of not less than three or more months, it could be discerned by the eye that additions greater or less had been made to the shore." The state of facts disclosed by this averment was held not to take the case out of the law concerning accretion, and, after referring to some English authorities, it was said: "The doctrine of the English cases is, that accretion is an addition to land coterminous with the water, which is formed so slowly that its progress cannot be perceived, and does not admit of the view that in order to be accretion the formation must be one not discernible by comparison at two distant points of time." And then was quoted from the opinion in St. Clair v. Lovingston, 23 Wall. 46, these words: "The test as to what is gradual and imperceptible in the sense of the rule is, that though the witnesses may see from time to time that progress has been made, they could not perceive it while the process was going on."

The case before us is presented on testimony, and not on allegation. But what are the facts apparent from that testimony? The Missouri River is a winding stream, coursing through a valley of varying width, the substratum of whose soil, a deposit of distant centuries, is largely of quicksand. In building the bridge of the Union Pacific Railway Company across the Missouri River, in the vicinity of the tracts in controversy, the builders went down to the solid rock, sixty-five feet below the surface, and there found a pine log a foot and a half in diameter- of course, a deposit made in the long ago. The current is rapid, far above the average of ordinary rivers; and by reason of the snows in the mountains there are two well known rises in the volume of its waters, known as the April and June rises. The large volume of water pouring down at the time of these rises, with the rapidity of its current, has great and rapid action upon the loose soil of its banks. Whenever it impinges with direct attack upon the bank at a bend of the stream, and that bank is of the loose sand obtaining in the valley of the Missouri, it is not strange that the abrasion and washing away is rapid and great. Frequently, where above the loose substratum of sand there is a deposit of comparatively solid soil, the washing out of the

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underlying sand causes an instantaneous fall of quite a length and breadth of the superstratum of soil into the river; so that it may, in one sense of the term, be said that the diminution of the banks is not gradual and imperceptible, but sudden and visible. Notwithstanding this, two things must be borne in mind, familiar to all dwellers on the banks of the Missouri River, and disclosed by the testimony: that, while there may be an instantaneous and obvious dropping into the river of quite a portion of its banks, such portion is not carried down the stream as a solid and compact mass, but disintegrates and separates into particles of earth borne onward by the flowing water, and giving to the stream that color which, in the history of the country, has made it known as the "muddy" Missouri; and, also, that while the disappearance, by reason of this process, of a mass of bank may be sudden and obvious, there is no transfer of such a solid body of earth to the opposite shore, or anything like an instantaneous and visible creation of a bank on that shore. The accretion, whatever may be the fact in respect to the diminution, is always gradual and by the imperceptible deposit of floating particles of earth. There is, except in such cases of avulsion as may be noticed hereafter, in all matter of increase of bank, always a mere gradual and imperceptible process. There is no heaping up at an instant, and while the eye rests upon the stream, of acres or rods on the forming side of the river. No engineering skill is sufficient to say where the earth in the bank washed away and disintegrating into the river finds its rest and abiding place. The falling bank has passed into the floating mass of earth and water, and the particles of earth may rest one or fifty miles below, and upon either shore. There is, no matter how rapid the process of subtraction or addition, no detachment of earth from the one side and deposit of the same upon the other. The only thing which distinguishes this river from other streams, in the matter of accretion, is in the rapidity of the change caused by the velocity of the current; and this in itself, in the very nature of things, works no change in the principle underlying the rule of law in respect thereto.

Our conclusions are that, notwithstanding the rapidity of

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the changes in the course of the channel, and the washing from the one side and on to the other, the law of accretion controls on the Missouri River, as elsewhere; and that not only in respect to the rights of individual land owners, but also in respect to the boundary lines between States. The boundary, therefore, between Iowa and Nebraska is a varying line, so far as affected by these changes of diminution and accretion in the mere washing of the waters of the stream.

It appears, however, from the testimony, that in 1877 the river above Omaha, which had pursued a course in the nature of an ox-bow, suddenly cut through the neck of the bow and made for itself a new channel. This does not come within the law of accretion, but of that of avulsion. By this selection of a new channel the boundary was not changed, and it remained as it was prior to the avulsion, the centre line of the old channel; and that, unless the waters of the river returned to their former bed, became a fixed and unvarying boundary, no matter what might be the changes of the river in its new channel.

We think we have by these observations indicated as clearly as is possible the boundary between the two States, and upon these principles the parties may agree to a designa tion of such boundary, and such designation will pass into a final decree. If no agreement is possible, then the court will appoint a commission to survey and report in accordance with the views herein expressed.

The costs of this suit will be divided between the two States, because the matter involved is one of those governmental questions in which each party has a real and vital, and yet not a litigious, interest.