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By E. P. Humphrey

The Lehigh Valley Coal Co. finished the rebuilding of its Drifton No. 2 breaker at Drifton, Pa., in the summer of 1917. The new construction comprises an addition and the complete remodeling of the old breaker. It is of interest to note that the old structure was the first iron breaker erected in the anthracite region. The Old Breaker This old breaker was built by the Cross Creek Coal Co., under the direction of the late Eckley B. Coxe, in 1888-89, and was fully described by him in the Transactions1. The columns were cast iron, 8, 10 and 12 in. square. The floors and partitions in pockets were cast-iron ribbed plates. The struts were cast iron of "H" section; the other members were of structural iron either rolled I-beams or built-up sections. The sizes of the rolled beams varied from 6 to 20 in. deep, while the built-up sections, made of plates and angles, varied from 6 to 63 in. in depth, so that there apparently was no rule to determine the type of section used. In the remodeling of the old structure, practically everything was taken down excepting the columns and roof, and such beams as were necessary for temporary construction purposes, and, therefore, a close inspection of the old structural members could be made and the effect of the acid water on them could be noted. The cast-iron members were but slightly attacked by the water, while the wrought-iron beams, in the wet places, were corroded almost to failure. The following are analyses of cast-iron, wrought-iron, and structural-steel samples taken from the old and the new structure.

Jan 1, 1918

Discussion of the papers of Messrs. Howe and Levy, Burgess, Crowe and Rawdon, and H. M. Howe, presented at the New York Meeting, October, 1913, and printed in Bulletin No. 78, June, 1913, pp. 1075 to 1136. ALFRED STANSFIELD, Montreal, Canada :-In Professor Howe's paper on the position of Ae3, he shows its industrial importance in determining the temperature to which steel should be heated. for "grain refining." Several years ago I carried out a research on the " burning " of steel and found that while hypo-eutectoid steel should be heated to Ae3, hyper-eutectoid steel that has been very much overheated must be reheated to the curve Sa on the carbon-iron diagram, in order to redissolve the pro-eutectoid cementite and thus, to obtain recrystallization and grain-refining. This treatment was necessarily only partly successful, and I should like to ask whether the conditions of heat treatment for refining overheated high-carbon steels have been ascertained. Speaking of the " Persistence of Solidificational Segregation " Professor Howe quotes an experiment made by Mr. Stead in which a bar of 1.2 per cent. carbon steel was immersed in a large mass of molten blast-furnace slag and allowed to cool with it. The steel was heated above the solidus (curve Aa on the carbon-iron diagram), but below the liquidus (curve AB). A drop of eutectic carbon-iron alloy, rich in carbon, had liquated out and hung below the bar. This agrees exactly with my own observations on the burning of steel, but my interpretation differs somewhat from that of Professor Howe. Professor Howe considers that the fusion of a part of the metal (rich in carbon) shows that the solidificational irregularities of composition had persisted through the rolling and heat treatment of the steel, as otherwise no part of the steel would have been sufficiently fusible to melt. It does not appear to me that such an explanation is necessary. A piece of steel represented in temperature and composition by any point within the area ABa will ultimately resolve itself into a solid phase and a liquid phase in equilibrium with each other. It may appear that if the steel were absolutely uniform no fusion could take place, but the smallest nucleus of high-carbon, fusible alloy would ultimately bring about this separation into liquid and solid phases, by diffusion of the carbon from the solid to the liquid areas. A nucleus sufficient for the purpose might be provided by an area of pro-eutectoid cementite which had not become diffused during the

Jan 12, 1913

By Thomas A. Edison, John Birkinbine

The Transactions already contain many valuable papers on the subject of ore-concentration, but with reference more to the treatment of other ores than those of iron. In this country much money, labor and thought have been devoted to the enrichment of iron-ores by roasting to drive off sulphur and carbonic acid, eliminate water, or make the ore more friable, and by washing and screening to remove the clay and sand from earthy ores. In concentrating magnetites and hematites more has been done than is generally believed; but, unfortunately, the results up to the present time have not been encouraging. On the contrary, so many attempts have proved unsatisfactory that any system of concentration is now unjustly looked upon with doubt, and the problem presented to individual mines must therefore be approached with caution. For many years the magnetites of the Adirondack region of New York State have been roasted, reduced to proper size by means of gang-stamps, and jigged on screens in water. Latterly plunger-jigs and rotary-jigs have been introduced, and in some places crushers and rolls have taken the place of stamps. In one instance in that region a plant for reducing the ore by crushers and rolls and separating it by magnetism was put up to treat a titaniferous ore; but, the titanium occurring as ilmenite, the result was unsatisfactory, and the plant is now being reconstructed at another mine, where apatite and silica are to be separated from the magnetite. A large concentrating works was erected at Negaunee, Michigan, in the Marquette region, Lake Superior, to enrich the leaner specular ores. This consisted of crushers, Cornish rolls and rotary-jigs. The results ohtained weye not satisfactory, and it has been abandoned. Another plan to treat the lean magnetites from a large dump-pile at Republic, Michigan, by means of pulverizers and water-jigs also

Jan 1, 1889

By Sterling G. Valentine

Until within late years, the preparation of sulphurous ores for the blast-furnace has received comparatively little attention. After the first improvement made on the old style of heap-roasting and roasting between walls, there has followed an almost general adoption of the Gjers kiln or some modification thereof, and the majority of iron-masters have seemed perfectly satisfied with so much progress. However, the Westman kiln was developed in Sweden, and other gas-roasters for sulphurous ores have been since constructed. They are in use on the continent of Europe and in America to a limited extent. The following experiments were made in order to furnish additional information as to the proper conditions for the elimination of sulphur from ores where it is present as sulphide of iron, FeS2 I desire here to acknowledge the Kindness of Dr. Franklin Menges, of the laboratory of Pennsylvania College, at Gettysburg, Pennsylvania, for lending his valuable aid in carrying out a part of these experilnents and analyses. In the first series of these experiments, pure, roughly-pulverized pyrites crystals were used, containing 53.42 per cent. of' sulphur. They were made with a view to determine the effect on pyrites, of heat alone, in various degrees of intensity and duration, air being altogether excluded. The heats at a low temperature were made in glass combustion-tubes, sealed at the end, where the pyrites to be tested were placed, and with only a small opening at the opposite end. Although not allowing circulation, this arrangement still permitted a part of the evolved sulphur to escape. The heats at high temperatures were made in Hessian and graphite crucibles, tightly luted, every precaution being taken to exclude air. The temperatures attained are given approximately, and are as nearly correct as it was possible to estimate them, using Pouillet's scale as a guide.

Jan 1, 1890

By David Donoghue

THE. years 1901, 1910, and 1924 may be considered as the beginning of new eras in the history of the oil industry of the Gulf Coast of Texas and Louisiana. Spindletop, in 1901, with its enormous cap-rock production revealed the possibilities of the salt domes. The lateral sand development at Vinton, in 1910, renewed interest in the then known domes which were non-producing, or were producing from the cap rock or from sands above the cap rock. The discovery of three domes, Nash, Orchard and Long Point, in the year 1924, by means of the torsion balance and the seismograph, is the beginning of intensive explorations of the Gulf coastal plain by geophysical methods. Domes other than those mentioned have no doubt been found during the last few months of the year but tests have not been drilled to confirm the evidence of the instruments. DISCOVERY OF DOMES BY GEOPHYSICAL METHODS The Rycade Oil Corpn. operated the first torsion balance on the Gulf Coast in October, 1922, and the Roxana Petroleum Corpn. brought in one of these instruments and began work in December, 1922. The U. S. Coast and Geodetic Survey made some gravity observations at Damon Mound, in 1923, with a pendulum apparatus. In March, 1924, the Marland Oil Co. placed the first seismograph on the Gulf Coast and the Gulf Production Co. followed with one in May. In June, 1924, the Gulf Production Co. began operations with a torsion balance. The Atlantic Oil Producing Co., The Texas Co., and others have experimented with several types of instruments involving various principles. During the next few years, a great advance in geophysical methods may be expected, especially if one of the newly discovered domes should be productive. The first dome discovered was the Nash, in Fort Bend County, Tex., about 6 mi. east of Damon Mound. A slight elevation and two shallow wells containing sulfurous waters made the locality somewhat interesting from the standpoint of surface indications, and the torsion-balance measurements indicated the presence of a dome. On July 20, 1924, the Rycade Oil Corpn. No. 1 Wisdom encountered lime at a depth of 634 ft. and anhydrite at 639 ft. The hole was abandoned on Sept. 8, 1924, at 769 ft. in anhydrite. A cavity in the anhydrite caused much delay and the final abandonment of this test.

Jan 3, 1925

By N. M. Langdon

The calculation of slags may be considered under three cases: I. A certain percentage of silica is required, it being known, in a

Jan 1, 1893

By Roy A. Hardy

The Getchell mine is a comparatively recent discovery in the old Potosi mining district, Humboldt County, Nevada, a district organized in the seventies and eighties, in which some prospecting was done in several metamorphic zones along a monzonite-sedimentary contact. The district had no production in the early days and no further work was done until the same metamorphic zones were prospected for tungsten (scheelite) in 1917 and 1918, when a few small lots were shipped. It again lay dormant until 1934, when prospectors investigated a large siliceous escarpment at one end of the old district where outcroppings were a prominent feature of the topography. Undoubtedly, during the early prospecting of the district, the outcroppings had been investigated for mineral, probably by panning, with negligible results because the gold later found is invisible in the concentrate and is refractory. A fire assay revealed the presence of sufficient gold to warrant development work. The outcroppings were easily prospected by short tunnels having their portals in the siliceous material on the hanging-wall side, with a maximum distance to crosscut to the footwall of 135 ft., or a distance at right angle to dip of 60 to 90 ft. Development work, reaching a depth of over 600 ft. on the dip of the vein, was done by means of various crosscut tunnels, winzes and laterals. A churn-drill hole was also sunk, which intersected. the vein at a depth of 1100 ft. on the dip. Sufficient development work of this character was completed by 1937 to justify the erection of a reduction plant to roast the sulphide ore and cyanide the calcine, and to treat the oxidized ore by straight cyanidation, to make a doré bullion for shipment to the mint. The erection of the plant was started that year and finished early in 1938; with a combined capacity of about 800 tons per day. It has operated continuously since erection and recently was enlarged to handle 1000 tons per day. The vein dips with the slope of the mountain, and by stripping the hanging wall the ore may be mined by power shovel for several hundred feet below the outcrop. Thereafter underground methods will be necessary.

Jan 1, 1941

By Roy A. Hardy

The Getchell mine is a comparatively recent discovery in the old Potosi mining district, Humboldt County, Nevada, a district organized in the seventies and eighties, in which some prospecting was done in several metamorphic zones along a monzonite-sedimentary contact. The district had no production in the early days and no further work was done until the same metamorphic zones were prospected for tungsten (scheelite) in 1917 and 1918, when a few small lots were shipped. It again lay dormant until 1934, when prospectors investigated a large siliceous escarpment at one end of the old district where outcroppings were a prominent feature of the topography. Undoubtedly, during the early prospecting of the district, the outcroppings had been investigated for mineral, probably by panning, with negligible results because the gold later found is invisible in the concentrate and is refractory. A fire assay revealed the presence of sufficient gold to warrant development work. The outcroppings were easily prospected by short tunnels having their portals in the siliceous material on the hanging-wall side, with a maximum distance to crosscut to the footwall of 135 ft., or a distance at right angle to dip of 60 to 90 ft. Development work, reaching a depth of over 600 ft. on the dip of the vein, was done by means of various crosscut tunnels, winzes and laterals. A churn-drill hole was also sunk, which intersected. the vein at a depth of 1100 ft. on the dip. Sufficient development work of this character was completed by 1937 to justify the erection of a reduction plant to roast the sulphide ore and cyanide the calcine, and to treat the oxidized ore by straight cyanidation, to make a doré bullion for shipment to the mint. The erection of the plant was started that year and finished early in 1938; with a combined capacity of about 800 tons per day. It has operated continuously since erection and recently was enlarged to handle 1000 tons per day. The vein dips with the slope of the mountain, and by stripping the hanging wall the ore may be mined by power shovel for several hundred feet below the outcrop. Thereafter underground methods will be necessary.

Jan 1, 1941

By H. M. Chance

One hundred and twenty miles of hard travel over steep ridges almost due east from Fayetteville, on the St. Louis and San Francisco Railroad, about 100 miles from Eureka Hot Springs, or 75 miles northwest from Batesville, will bring the traveller to the waters of the Buffalo Fork of the White river, in a wild, thinlysettled, heavily-timbered country, now being prospected quite actively for zinc, and known as the Buffalo or Rush Creek district. Excepting here and there a piece of bottom land, patented before the discovery of zinc, the land is unoccupied Government land, and subject to entry under the United States mineral laws. Claims are now being taken, 600 by 1500 feet, but a movement made this summer, if successful, will largely modify the position of claim-holders. A few claims are now being filed under the Placer Act on the ground that as the zinc occurs as a horizontal, sedimentary deposit, etc., it can only be properly so classified. The zinc occurs in limestone, which is at times so siliceous that

Jan 1, 1890

By P. H. Scott, Walter Rose

Recent papers by S. T. Yuster have called attention to the largely ignored concept that there will be a transfer of viscous forces across fluid-fluid interfaces during the flow of immiscible fluid phases through porous media. This leads to the implication that the relative permeability us saturation function, as applied to each of the fluid phases of the system, will in some way be dependent on the viscosities of all the other fluid phases which are contiguous to the flowing fluid of interest. In fact, Yuster has selected and analyzed the properties of a capillary-tube model of the reservoir-prototype flow systems and concludes from his studies that relative permeability values will be very markedly influenced by the viscosity ratio in two-phase systems. On the other hand, relative permeability data have been reported in the literature for more than 20 years; and where these data are consistent at all, they consistently how no dependence on viscosity ratio (cf. chapter 7 of Muskat3 for a resume of past experiniental work). This paradoxical situation has prompted us to re-evaluate Yuster's work. The major flaw we find has to do with the properties of the model Yuster employed to give qualitative support to his predictions. This model is defective in that important surface area parameters characteristic of the prototype-reservoir flow system have not been propertly scaled. Fig. 1 shows how we believe Yuster's model should be modified to circumvent this difficulty. It depicts the capillary tube of radius R and length L, comprised of two elements in series. The first part of length, L has the nonwetting phase flowing centrally out to a radius distance r, where an interfacial boundary exists with the wetting phase which flows in the concentric annular pace of the tube. The second part of length, L-L,. has the

Jan 1, 1953

By George Smith

TWELVE years ago, the Director of the United States Geological Survey addressed to the Secretary of the Interior a letter calling attention to the government's need for liquid fuel for naval use and pointing out that the rate of increase in demand was more rapid than the increase in production.1 This letter, in a way, inaugurated the policy of public oil-land withdrawals, which was well founded in its primary purpose of protecting the oil industry and highly desirable in its immediate effect of checking the over-development of that day in California. Unfortunately, however, through delays in legislation, this policy may be regarded now as having outlived both its intent and its usefulness. In 1908, the country's production of oil was 178,500,000 bbl., and there was a surplus above consumption of more than 20,000,000 bbl. available to go into storage.: In 1918, 10 years later, the oil wells of the United States yielded 356,000,000 bbl.-nearly twice the yield of 1908-but to meet the demands of the increased consumption more than 24,000,000 bbl. had to be drawn from storage. Nor is this all of the brief comparison. In 1918, our excess of imports over exports of crude petroleum was nearly 33,000,000 bbl. whereas in 1908 we exported 3,500,000 bbl., which was net, as we had not begun to import Mexican oil. In this period, the annual fuel-oil consumption of the railroads alone has increased from 16,871,000 to 36,714,000. bbl.; the annual gasoline production from 540,000,000 gal. to 3,500,000,000 gal. This record may be taken not only as justifying the earlier appeal for Federal action, but as warranting deliberate attention to the oil problem of today.

Jan 1, 1920

By William M. Brewer

Until quite recently, in fact within the past two gears, but little attention has been given to the outcrops on the west coast of Vancouver Island, and their copper-contents. During the past few months the writer has been engaged in examining and developing some of these prospects. In many respects he has found characteristics associated with these prospects which, in his experience, are unique. In the first place, nearly all the outcroppings which overlie chalcopyrite-ore along the west coast of the island are composed of a high-grade magnetite. The magnetic qualities of some of these outcrops arc so pronounced that the magnetite possesses polarity. Although the writer hinlsclf had no analyses of this magnetite made, yet from its appearance he can readily believe that analyses made for other parties, which show a yield' of 62 or 63 per cent. of metallic iron, with only traces of phosphorus and silica, are correct. At a very shallow depth, masses of chalcopyrite, yielding in some instances as high as 32.6 per cent. of copper, occur associated with the magnetite; and in one instance, which recently came under the writer's observation, a solid body of high-grade chalcopyrite, fully 4 feet in thickness, occurs Within 6 feet of ; the surface. Usually this solid sulphide-ore carries low values in gold. Probably ail average of' $2 per toil would be fairly representative. But in some instances development has determined the occurrence of narrow stringers of pyritous quartz, associated with the sulphide-ores, which yield by assay more than $20 per ton in gold. In the districts examined by the writer, the country-rock is usually crystalline limestone, with dikes of igneous rock as intrusions. Sometimes the outcrops of magnetic iron-ore are

Jan 1, 1900

By J. J. Marcus

Mineral industry decision-makers are frequently required to select between competing equipment. Various criteria and methods are currently being used, and this writer would like to suggest a method recently tested on two large power shovels in an open pit mine. An initial examination of both shovel A and shovel B indicated that the latter should give the best overall results. since: 1) It swings 13% faster; 2) it carries a dipper with 23%: greater capacity; 3) purchase price is 8.6% lower; 4) shovel weight is 12.5% greater; 5) it has considerably greater bail pull under most operating conditions; 6) the electric controls are of a more modern design. However, shovel B has half the service life. With these points in mind, shovel A was selected by The Buckingham Method, an operations research technique.

Jan 9, 1965

By R. G. Baughman

With the constantly increasing sales competition, coal to be sold today must meet the test of quality in every respect. The producers must be able to make all marketable sizes that will meet such general requirements as follows: 1. Ash content must be consistently low, depending upon the use to be made of the coal. 2. Sulfur content must be controlled accurately according to requirements. 3. All sizes must be positively free from visible impurities. 4. Free moisture of washed sizes must be reduced to a minimum. 5. The freezing of wet coal in cars must be prevented. 6. The percentage of fines in small mixed sizes must be controlled to give the uniform and proper combustion when used on various types of automatic stokers. 7. The undersize particles or degradation caused by handling must be kept to an absolute minimum in all sizes loaded. Many difficulties may be met in bringing any particular coal to meet these quality requirements, because the extent to which the quality of a coal may be controlled is determined largely by its physical characteristics. Preparation of an Impure Coal Bed The application of modern and scientific methods in the controlled preparation of bituminous coal from a bed in the mid-western field will illustrate the results that can be accomplished by adequate preparation: The bed referred to contains coal inherently excellent as to low ash and other desirable characteristics; in fact, the coal itself is one of the best in the field. It is, however, divided into four layers by dirt bands of soft shale 1 to 2 in. thick. It also contains much sulfur in the form of sulfur lenses and laminated sheets. Horsebacks or rolls varying from 6 in. to 12 ft. in width are encountered in the mining of the bed and heretofore have rendered it practically unworkable. The mines operating in this

Jan 1, 1931

By A. W. Edelen

THE Teziutlan copper-zinc deposit is supposed to be of late Cambrian or early Paleozoic age. The country rocks are a series of schists or phyllites, flat lying and in the form of a plunging anticline. The ore deposit occupies a single horizon in the schist for a known horizontal extent of 1200 meters. Along its strike occur four large lenses or ore bodies. These ore bodies occupy positions along the flank and extend to the crest of the anticline. The primary mineralization is in the form of quartz, pyrite, sphalerite, chalcopyrite and galena, with a few scattered silver anti-monides. Quartz and pyrite form the mineralization between the ore lenses. In the ore lenses the sulphides appear as a massive, very fine-grained intergrowth of minerals. The intergrowth suggests a contemporaneous deposition of the heavy sulphides. The grain size, usually under 0.09 mm., makes the separation difficult and fine grinding important. The ore bodies were formed at great depth by solutions probably originating in the same basic magma that gave rise to the dolerite sills that are so common in their vicinity.

Jan 1, 1937

By H. R. Banks

THE Sullivan concentrator has completed 20 years of operation. During this period a considerable amount of data has been accumulated concerning the characteristics of several types of flotation machines in their application to the problem of the differential separation of the lead sulphide, zinc sulphide and, in more recent times, iron sulphide, in the ore from the Sullivan mine. It is the author's intention to sketch briefly experiences encountered when the several types of flotation machines were introduced into the flow. ORIGINAL FLOTATION EQUIPMENT AND ORE The original flotation equipment consisted of four 18-cell lead-roughing machines, whose concentrate was cleaned in an 8-cell and recleaned in a similar 8-cell machine. Zinc concentration was carried out in four 18-cell machines. One 8-cell zinc re-treatment machine received the reground zinc middling. The 168 cells handled some 3000 tons of original daily feed. These cells were of the standard Minerals Separation type, equipped with 24-in. impellers. Spindles were driven through geared line shaft at a speed of 255 r.p.m. The impellers were the 45° type, except for the last three cells of the zinc-rougher machines, which were of sub-aeration type, with full bottom shroud and half shroud for the top side of the impellers. Four-pound air was introduced. This recognition of the benefit of intensified flotation operation for "gleaning" was an important phase in the early operation and will be discussed further on in this paper. Sullivan ore during this period is described as a finely disseminated mixture of four sulphides, totaling 90 per cent made up of 13.6 per cent galena, 14.4 per cent marmatite, 1 per cent pyrite and 61 per cent pyrrhotite. The specific gravity of the ore was approximately 4.4. There has been a gradual change in the ore content. The 10 per cent of nonsulphide constituents has increased to between 15 and 20 per cent and all three sulphides have dropped somewhat. Added equipment and changing technique have made possible the treatment of 8000 tons per day of mill feed instead of the 3000 originally handled. SPECIAL FEATURES OF FLOTATION AT SULLIVAN Sullivan flotation differs greatly from customary practice. The very heavy return of lead rougher middling and lead cleaner tailing, totaling at times 125 per cent of the new feed tonnage, has been the subject of much investigation. The practice is still employed.

Jan 1, 1944

By AIME AIME

ONE test is worth a thousand expert opinions, say the engineers of the John A. Roebling's Sons Co. of Trenton, N. J. Confronted with the job of building the cables for the new Hudson River Bridge between Fort Lee and upper Manhattan, the Roebling organization, in spite of its long and varied experience in building cables for suspension bridges of various sizes, recognized that old yardsticks would be of little value in estimating safety factors for the immense span across the Hudson.

Jan 1, 1929

By R. W. Raymond

I HAVE the pleasure of exhibiting samples of the rock in which the South African diamonds are said to occur, for which I am in debted to Mr. Franz Groeger, of Vienna, formerly an assistant of the Royal Imperial Geological Institution, whose account of the general geology of Southern Africa was contained in a recent number of the proceedings of that Institution. The rock is apparently a sort of tufa, evidently of volcanic origin. Mr. Groeger assured me that it could be seen in situ, bounded by uplifted stratified rocks; and that diamonds had been mined from it, by means of shafts, some distance below the surface. Groeger calls it "greenstone-tufa," and says of it, in the proceedings of the Geological Institution, " it breaks through the younger members of Group III [lower Trias and Jura], . . .. and crops out in oval masses, filling fissures . . ..The occurrence of this tufa is not locally limited, but has been traced and proved already over a large territory." DR. HUNT remarked that the material looked like the trass of the Rhine region. He thought it a new occurrence for diamonds. He believed diamonds to belong to ancient crystalline rocks, although these materials might be brought tip by volcanic agency, and the diamonds remain unaltered. In the volcanic rocks of Auvergne, crystals of sapphire, zircon, and spinel are found; and yet no one supposes that these minerals have been generated by volcanic agency. He had had a conversation with Bertrand de Lom on this subject, who agreed with him that these minerals, being hard and resistant,

Jan 1, 1874

By John A. Shelton

One of the heaviest burdens uselessly cast by our mineral land laws upon the holder of the title conveyed by a patent from the United States is due to the provision excepting known veins from land patented as placer. In many instances the expense of defending such titles from the assaults of the owners of lode locations made upon the theory that the veins so located were known to exist at the date of the placer application for patent has exceeded many times the value of the land in question. Neither the lapse of time, however long after the issuance of the patent. nor repeated adjudications by the courts serve to quiet such titles Or to prevent them from being questioned. In the passage of laws providing for the acquisition of title to the mineral lands of the United States, Congress provided that the title to known veins should not pass from the United States by a patent based upon a placer location. As construed by the courts, the law (Sec. 2333 R.S.U.S.) provides that the applicant for a patent upon a placer claim may, if any vein of sufficient value to justify the expenditure of money in its development is known by him to exist within the boundaries thereof, include in his patent application an application for patent upon the vein as a lode claim; and failure to do so is to be deemed a conclusive declaration that the applicant makes no claim to the vein nor to an area of surface ground extending for 25 ft. (7.6 m.) on each side of its middle or center. As to such vein and such area of enclosing surface ground under the circumstances stated, the title remains in the United States notwithstanding the issuance of a patent that purports to convey the entire surface of a described area and everything beneath it, excepting only the segments of veins the apices of which lie outside of such area. Such known veins with such area of enclosing surface ground are, of course, at any time, so long as they remain unlocated, subject to location and appropriation in the same manner as other. veins upon the public domain. The history of the operation of this law in one district will serve to illustrate its effect generally throughout the mining regions of the United States. In the Butte district, the mineral that first attracted the atten-

Jan 1, 1920

By Henry M. Howe

What should be the chief aim of a metallurgical laboratory ? Before answering this, let us ask, What should be the chief aim of metallurgical instruction ? Taking a definite case, that of the iron blast-furnace, should we chiefly teach the methods of bosh- and tuyere-cooling, of storing and assembling materials, of removing the iron and cinder, of firing boilers and cleaning stoves ? Or should we aim chiefly to lay clear and bare the nature of the reactions which occur in the blast-furnace, the reason why changes in the rate of driving, in the blast-temperature, in the composition of the cinder, cause their known effects ? Shall we chiefly describe or explain ? Shall we teach chiefly the looks or the reasons ? Put thus, the question admits but one answer. Hours of labored description at a technical school give a less true and clear view of actual metallurgical operations than a brief visit to metallurgical works. If in my teaching 1 take the far more laborious course and lay so very great stress on explanation and so little on description that I seem to err on that laborious side and not to give description enough, the student will quickly make up for my lack of description in his first weeks in the works; he will there learn quickly and easily what I could have described only obscurely and with labor. Details of practice are learned easily and retentively in the works, but with difficulty and slowly at school. With the principles, and especially the chemical principles of metallurgy, the reverse is true. The works have little facility for teaching them; the school has every facility. The place then for explaining, for teaching principles, is the school. But,

Jan 1, 1900