garded as one of the authors, and the chief representative of that classification. But I leave to other hands the theoretical discussion of the phenomena, and of the principles, both of geology and of mining law, illustrated by them.

THE EUREKA-RICHMOND CASE.

BY ROSSITER W. RAYMOND, PH.D., NEW YORK CITY.

(Read at the Amenia Meeting, October, 1877.)

In the case of The Eureka Consolidated Mining Company v. The Richmond Mining Company of Nevada, recently tried at San Francisco, California, the real defendant was the Richmond Consolidated Mining Company, of London; but this being a foreign corporation, holds its mining property in Nevada through the Nevada corporation of similar name, in which the London Company owns all the stock, except the few shares necessary to "qualify" the American directors. The trial would naturally have taken place in the Circuit Court at Carson City, Nevada, and before a jury. But by stipulation of the parties, the case was tried in San Francisco, before Hon. Stephen J. Field, Justice of the Supreme Court of the United States, Hon. Lorenzo Sawyer, United States Circuit Judge of the Ninth Circuit, and Hon. E. W. Hillyer, United States District Judge, for the District of Nevada. The hearing began July 23d, 1877. The witnesses occupied two weeks, and the argument of counsel three days. Very eminent lawyers were engaged on both sides; for the plaintiff, Messrs. Solomon Heydenfeldt, R. S. Mesick, John Garber, and H. J. Thornton; for the defendant, Messrs. S. M. Wilson, Thomas Wren, and J. J. Williams. The court held the case under advisement until August 22d, when Mr. Justice Field delivered its unanimous opinion in favor of the plaintiff. The action was a complaint in ejectment, and an appeal was taken to the United States Supreme Court.

The questions at issue between the Eureka and the Richmond Company in this suit, comprised several points in the construction of the mining law of the United States, and its relation to the customs and regulations of the mining districts, which possess an importance and an applicability far beyond the limits of the case in which they arose. It is my purpose to state these points, the arguments

concerning them on both sides, and the grounds on which they were decided by the court. The case involved also an interesting discussion of the nature and process of formation of the argentiferous lead deposit of Ruby Hill, which I shall attempt to sketch. For a description of the locality and its vein-phenomena, I refer to the elaborate paper of Mr. W. S. Keyes, which is presented to the Institute simultaneously with this one, and to which this is intended as a companion. Mr. Keyes's paper being accompanied with accurate maps, it will be unnecessary for me to offer any such illustrations of the statements herein made.

The contest between the two companies turned upon two questions: First. Are the two mines working upon the same vein or lode, within the meaning of the law? Secondly. If they are upon the same vein, where should the boundary-plane be drawn between them? And if upon different veins, how are the respective rights of the parties affected by the locations, patents, and former agreements?

The first question involved two inquiries. The first of these relating to the nature of the deposit in dispute, and the theory of its formation, possesses a scientific interest outside of its application to the immediate argument; the second, relating to the meaning of the terms, "vein," "lode," and "ledge," as used in the United States law, is universally applicable to mines held by titles proceeding from that law.

Again, this latter inquiry involves an investigation of the popular and scientific usage of the terms referred to, and of the bearing of strict geological classifications upon questions of mining rights.

It involves also a determination of the force of a boundary-line, established between two mines on the surface, and the direction of its projection in a plane underground.

1. THEORY OF THE FORMATION OF THE RUBY HILL DEPOSIT.

It was admitted on both sides that the ore-bodies of Ruby Hill occur in a zone of limestone, lying upon quartzite, and highly tilted and broken up; that none of the fissures in this limestone had been found to penetrate the quartzite or to pass beyond a certain layer of argillaceous shale, alleged to bound this limestone zone on the hanging-wall side. This clay or shale has been exposed in numerous places, by cross-cuts underground, at varying distances from the quartzite. It is also visible on the surface. The experts of the

Eureka Company considered it to be demonstrated as a continuous layer, and as a boundary of the ore-bearing limestone. Beyond it, they found limestone again, which they described as different in character and appearance from that within the ore-bearing zone. Microscopic slides were produced, to show that in its minute structure, the limestone of the zone shows the result of crushing, disintegration, solution, infiltration, recementation, and mineral deposition, which are comparatively absent from the exterior overlying limestone. Both are magnesian. The experts of the Richmond Company did not deny (I think) that the layer of argillaceous shale or clay might be continuous; but they thought this was not proved, and some of them believed the different exposures made of it to have no connection with each other. They denied also any essential difference between the limestone within and without the alleged zone. While the facts as there developed left room for differences of opinion on these points, the great preponderance of probability as to the existence of a continuous boundary on the north of the ore-bearing limestone zone, in the form of a layer of shale, lies with the affirmative. The fact is, indeed, as clearly proved as the nature of the case would permit. As to the difference in the limestones above and below (north and south of) this layer, one fact was necessarily admitted,—that no ore-bodies have been found near it on the north side, while the limestone zone on the south contains numerous and extensive ones, and is of such a character that explorations anywhere in it may at any time expose ore. The bulges of the quartzite footwall, described in the paper of Mr. Keyes, were also admitted, under various names, by all the experts. Some called them capes; some spoke of the intervening spaces as bays or grooves in the quartzite. Some of the Richmond experts did not consider these irregularities in the surface of the quartzite as the results of pressure and "buckling," but thought they might have existed in the surface on which the limestone was deposited. This view was, however, not seriously insisted upon, and certainly does not, in my opinion agree with all the facts.

According to the theory held by the experts of the Eureka Company, the deposits of Ruby Hill, in their present form, are due to the following processes:

The quartzite is a metamorphosed sedimentary rock. It has been lifted, with the superincumbent limestone strata, to its present position, by forces connected with the general upheavals forming the north and south ranges of mountains in Nevada. The volcanic rocks

appearing to the eastward are probably connected with the same process. But it is noteworthy that the quartzite under Ruby Hill was lifted along a line departing from the north and south line of the mountains of which Ruby Hill is a spur. The strike of the Ruby Hill quartzite shows moreover that it was curved and doubled, as well as lifted. The result of this movement was, that the quartzite layer had less room in depth than along the present outcrop, and the uplifted quartzite formed a sort of basin, buckling or bulging in depth near the points of greatest curve in course. But this buckling of the quartzite could not take place without intrusion into the solid limestone above, and hence the limestone, subjected to oblique upheaval and torsion, and to the intrusion of the quartzite, was much more violently shattered and fissured than by an ordinary upheaval. The process need not have been rapid; a very slow operation of lifting, rubbing, and side-pushing, from the underlying quartzite, would account for the crushing of the limestone, and for the existence of smooth planes of movement, in various directions, upon masses of limestone not crushed, or upon aggregates once crushed and subsequently cemented together again.

This action was limited, comparatively, to the zone of limestone immediately overlying the quartzite. In this zone or layer, which may have been from two hundred to three hundred and fifty feet thick, there appears to have been no argillaceous strata. But at that distance above the quartzite there seems to have been a bed of clay-shale and lime-shale, along which the limestone beds in process of upheaval and contortion could part and slip. The slipping is traceable on the present clay hanging wall in all the mines of this series, from the Richmond to the Jackson; this clay being the remainder of the former laminated beds, from which percolating water has removed a portion of their lime. The present varying thickness of the clay is due, in large part, to the effects of the slipping, which has rubbed it thin in some places, to bunch it up in others. This clay dips from the surface more steeply than the quartzite, a peculiarity due to the internal movements of the limestone zone between them. There is no reason to doubt that the contact-planes between shale and limestone, limestone and quartzite, were originally parallel. But the side-presure attending the upheaval, causing the quartzite to buckle or bulge, and intrude upon the limestone, not only crushed and shattered the latter, but forced it to move in considerable masses to make room for the intruding "capes," or swellings of the footwall. These might push the fragments of limestone among themselves right and left, as

well as up or down, at first; but the fragments first moved, wedging among the pieces of broken limestone, still in place, would move them in some direction; and the general resultant of all these internal movements, would be to drive masses of fragments or solid wedges of limestone upwards toward the outcrop. The zone of limestone between the shale and the quartzite is, therefore, wider near the outcrop than it is below, because, near the outcrop it contains limestone which has been squeezed and jammed up into that portion of it from portions lower down on the dip. The lateral movements within the ore bearing zone were, perhaps, most extensive in the Jackson Mine, where the quartzite swings round to what appears to be its regular north and south course, and the convex curve of the quartzite has crowded the limestone aside in all directions, until the clay hanging wall and the quartzite are almost in contact, with a seam of ore between.

The limestone zone thus crushed and dislocated presents, on a large scale, the phenomena described under the head of "Veins of Attrition" (Contritionsgänge), in the treatise of Weissenbach, published posthumously by Cotta, in the first volume of the Gangstudien, Freiberg, 1850. The classification is partly quoted in Whitney's Metallic Wealth of the United States, Philadelphia, 1853. Weissenbach discusses chiefly under the head of Contritionsgänge, the processes by which fissure-veins are filled to greater or lesser extent with the products of the disintegration, crushing, etc., of the country rock of one or both walls. He says (p. 24), that in consequence of the movements of the walls, aided by decomposing influences, "the whole vein itself may be filled up with such crushed, split, shifted, and cemented fragments of the country rock." After describing these phenomena, as presented by fissure-veins intersecting the stratification, he continues: "Finally, this kind of products of crushing from the disintegrated country rock occur frequently in a perfectly similar manner along the lines of stratification and cleavage in the older schists." It is evident that whether the plane of the action be that of a fissure across the stratification, or that of a parting between two sedimentary rocks, or two layers of the same rock, the effect of the crushing of one wall to a certain distance by the movements and pressure of the other wall, would be to produce a zone of material full of fissures and interstices. And the aggregate of these interstices and fissures would constitute, in that case, the equivalent of a fissure open to receive liquid solutions or gaseous emanations of metallic ores, just as we say, when a river like the