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By J. B. STEWART

T HE position of each hole of any series of holes was carefully located by the surveyor, plotted in plan and elevation, and numbers assigned to them. The second series was staggered halfway between the first and so on for each succeeding series. Two and a, half to three months was frequently required to grout a series of holes calculated to insure safety for sinking a distance of 10 meters or say 33 ft. Naturally the initial operation called for drilling and grouting two series of holes but thereafter each sinking campaign required only one series of holes as shown in Fig. 8. The pump handling about 75 gal. per minute corresponds to 46 tons of grout or 6 tons cement delivered as a fair over-all average for the 24 hours. Thus 600 to 800 tons of cement was used for a single section of 33 ft. depth of shaft. One campaign used nearly 1100 tons of cement. Some holes were effectually sealed with as low as 30 tons, while many required 60, and some 80 to 90 tons.

Jan 1, 1926

By C. H. Herty

AN earlier paper on absorption of sulfur by the slag in the basic open-hearth furnace included a brief discussion of the absorption of sulfur during the melting period. The data available at that time showed that the amount of sulfur absorbed by the melting scrap was proportional to the sulfur content of the furnace gases, and the following statement was made: "The conclusion may be drawn from these results that if a gas entirely free from sulfur were used during the melting, any iron in direct contact with the gases would be completely, or nearly completely, desulfurized before it reached the bath proper." The experimental work discussed herein deals with absorption of sulfur by the melting scrap when fuels with both high and low-sulfur content were used. Before taking up the experimental work let us consider the process as a whole as to the "flow" of sulfur. The input of sulfur occurs in: 1, the hot metal charged; 2, the scrap; 3, the stone or lime charged; 4, the ores charged; and 5, the gas. Sulfur goes out of the furnace in the steel, the slag and the gas. The distribution of sulfur in the furnace depends on the sulfur concentration in each of these materials and on the equilibrium conditions between them.

Jan 1, 1926

By S. F. Shaw

IT IS generally recognized that the natural gas absorbed in petroleum plays the leading r6le in moving the oil through the sands to the well and supplies the energy that delivers the oil to the surface when the wells are flowing. It is the purpose of this paper to note the amount of oil that could be lifted by this gas if 100 per cent. efficiency were obtained and the efficiencies actually obtained in the use of this gas. An article in MINING AND METALLURGY,' stated that in a Wyoming field, with a pressure of 300 lb. per sq. in., there would be absorbed 65 cu. ft. of gas per barrel, or 1.55 cu. ft. per gal. of oil. The writer does not know if data have been obtained, by experiment, for pressures beyond those indicated in this article, therefore, for the purpose of illustration, he has projected this curve to obtain figures for pressures greater than 300 lb., although probably experiment will show that the extended line is not quite correct.

Jan 1, 1926

By WILLIAM SLOAN

B RITISH COLUMBIA in its mining activities is going ahead by leaps and bounds both in development and production. Mineral production for 1925 was $61,492,242 in value as compared to $48,704,- 604 in 1924, or an increase of about 26.2 per cent. This is a new record. It is the first time in the history of mining in British Columbia that we have gone over the fifty million mark. But we have got in the habit of making new records. The year 1924, with its mineral production of almost forty-nine million was a new record. And I am confident that when the mining history of 1926 is written it will be found that we have established yet another new record and that we can report another 25 per cent increase over 1925. What is the explanation? It is not only that the world is settling down, and settling up, after the war. It is not only that in the rebuilding, the refashioning in which all nations are busily engaged, the metals that come from our mines are needed. More than anything else, at least as far as we are concerned, it is because British Columbia has the resources and the fact that the province has been fortunate in recent years in finding men with the enterprise and the vision required to push ahead the labor of their development. From the ranks of our own people in Canada we have prospectors who have faith, energy and requisite knowledge. They are combing our hills season after season and they are of the type of manhood that does not know the meaning of the word quit. More and more these men are learning the importance of the guidance furnished by geological reports, and to an ever increasing extent such reports, thanks to the valuable work of the Canadian Geological Survey, covering areas little known to man, are made available to them-but it is recognized that in the opening up of our Province, containing within itself 372,000 square miles, it is essential that we should have the cooperation of our cousins on this side of the line as well as of our fellow citizens of the Dominion and of the Mother Country.

Jan 1, 1926

By J. T. Ryan

POISONOUS, irritating, or explosive gases are found in almost every industry, and manufacturers of gas masks are called upon to provide gas mask protection for a great variety of conditions, such as operators in horseradish factories, fumigators of homes and ocean liners, and men engaged in the manufacture of tetra-ethyl-lead, the new motor fuel. The modern type of gas mask and respirator, to provide protection against all such industrial gases, is an outgrowth of the gas mask developed during the World War to protect the soldiers against the poisonous war gases. So far, it has been possible to develop ample mask protection from all known noxious gases and fumes present in atmospheres encountered in mines, metallurgical works, and chemical and other industries, so long as there is sufficient oxygen present to support the flame of an oil lamp. The most important development of the gas mask was in providing protection against carbon monoxide- which is the noxious gas that mining men are most concerned with and, in fact, is the noxious gas that man is most frequently exposed to. This paper will be con- fined largely to the discussion of masks for underground use in metal mines. Gases that contaminate the normal air in mines can be divided into two classes: those that are given off normally by the workings, and those that are produced in mine operation.

Jan 1, 1926

By John A. Mathews

D R. CHARLES W. ELIOT, the great educator and philosopher-he of the five-foot book shelf-recently gave expression to a thought I had long been cherishing as a private opinion, when he said: "It is obvious that standardization has become a dangerous adversary of progress in both education and industry." This idea must have been more widespread than either of us knew, for some five years ago a writer of verse for one of the comic papers dealt with it at great length. I will quote only a few of his stanzas to illustrate his understanding of "A Standardized Existence" : A visitor at large, I stand Beneath a standard sky- Where everything is standardized To please the standard eye. Each tree is of a standard height, Each building is the same; Each man is uniform in height, And has a standard name. Above there is a standard star Beside a standard cloud, And a standard weather here prevails To please a standard crowd. With standard joy, and standard gain, The standard people live; And if there is one bit of pain T?is such as standards give.

Jan 1, 1926

By R. M. Bird

FEW persons outside of the foundry trade have any conception of the great variety of sands now regularly specified and furnished, nor of the differences in foundry practice frequently resulting from apparently minor changes in sands. Conditions in each locality where the sands are mined and prepared necessitate special equipment designed to perform the work efficiently. The description that follows of the foundry sand producing operations is typical of the areas in New York and New Jersey, and particularly refers to the operations of the George F. Pettinos Co.

Jan 1, 1926

By CHARLES SIMENSTAD

COAL preparation, or coal washing, is not a new subject to the Pacific Northwest. Most of the coals mined in this state smaller than lump, and nearly all such sizes mined on the Pacific slope of the Cascade mountains, require washing before marketing. A large proportion is being put through some washing process, but coal washing in this state, has not reached the efficiency it is practicable to obtain. In fields where the coal, as mined, contains less impurities, where working conditions make it practicable to eliminate some of these impurities under- ground, or where a large proportion of the run-of-mine coal is lump, coal preparation does not present the problem it does in our local field. Here the coal is associated with considerable impurities and the slack, or steam sizes, aggregate about 80 per cent. of the output. Therefore, approximately 80 per cent. of the coal mined must be washed to become a valuable fuel. Washing then becomes a major operation, as hand picking of the 20 per cent. of lump is a standard and comparatively simple operation. Some coal beds here are so interstratified with bone, of a more or less massive nature, that hand picking of lump is not economically efficient. In such cases the coal must be crushed fine enough for it to be freed from the bone, so that the two may be separated. Coal cleaning in this field, therefore, must receive skilled attention to purify this fuel and raise its stand- ard. Without greater efficiency in cleaning, the importation of coal from outside the state will be even greater than in the past.

Jan 1, 1926

By William F. Boericke

CONSIDERABLE waste of oil and grease in lubricating motors and other machinery results from the use of bearings that are not totally enclosed. There is also the likelihood of damage to the bearing through the accidental introduction of grit or dust both in the oiling process and after, unless the cover is entirely dustproof. With the ordinary sleeve bearing that is only partly enclosed, it is generally easier for a careless attendant to cause trouble through neglect than with the ball bearing type, which from its design, must be totally enclosed to give effective service, and needs a minimum of attention. At one of the large mining companies which has taken a leading part in reducing unit costs and pioneering new developments in mining machinery, ball bearings have been gradually supplanting the conventional type of sleeve bearings on many of their motors, centrifugal pumps, and other machines in the mines. This innovation is not recent, as substitution of ball bearings on mine motors was first tried out by this company in 1909. Since then an increasing number of such bearings have been put in. They are now favored because of increased operating efficiency and reduction in lubrication costs.

Jan 1, 1926

By Thomas T. Read

AT this time of the year, engineering schools are releasing a group of young men who probably are, on the average, in much the same attitude of mind as a person arriving at the terminal station of a railway journey; namely, of having a general idea of his objective, but having to make a decision as to just where he is going and how best to get there. The man leaving the train can at first follow the crowd, but it soon breaks up, as one goes one way and one another, until he has to choose his own course. The recent graduate may do the equivalent of following the crowd by accepting the first position offered, but this only postpones a decision as to where he is going and how best to get there. So many young engineers ask for advice as to what to do that the following statement has been prepared as an attempt to make a general answer to such queries. The engineer taking his first job should realize two fundamental relations. The first is that in electing to be an engineer he has elected to be a hired man. A consulting engineer has more freedom than a man on a regular pay roll, but he is also a hired man; hired for briefer periods at a relatively high rate, but under the necessity of simultaneously doing his consulting work and developing new retainers. There is nothing derogatory in being a hired man (all doctors, lawyers and clergymen are hired men), but the tardy realization that he is one seems to give many an engineer a mental jolt that can be avoided if he accepts it from the beginning.

Jan 1, 1926

By George A. Burrell, G. W. Jones, Frank M. Seibert

In this bulletin, the style of Bulletin 42 has been closely followed. Much of the material is reprinted on the following pages in its original form, and changes have been made only where manifestly neces- St,ry. Laboratory methods have been brought up to date. Some types of apparatus described in Bulletin 42 have now become obsolete and newer designs are described instead. The authors hope that this bulletin will be of as much service as was Bulletin 42.

Jan 1, 1926

By A. B. Hooker, L. C. IlsLey

Explosives have been fired electrically for several decades. Mountains have been tunneled, deep shafts sunk, extensive coal and metal mine workings excavated and, in times of war, railroads, buildings, bridges, and fortifications have been destroyed by means of electrically fired explosives. Modern engineering depends so much on explosives that their safe and efficient handling and especially their detonation are of prime importance to all those connected with the use of explosive agents. Electric shot-firing is only one method of igniting explosives, but it is rapidly spreading and because of certain inherent safety features should be encouraged. Data collected by the Bureau of Mines indicate that in the United States a large percentage of the blasting in quarries, shafts,· and tunnels, and from 15 to 25 per cent of the blasts in mining operations, are set off electrically. The Bureau of Mines is interested in electric shot-firing because of its use in mining, and especially because electric methods, when properly applied, are undoubtedly safer than other methods commonly used. Electrical problems of many kinds must be solved in dealing with the various phases of electric shot-firing. Success in using an electric detonator is closely linked with the resistance of its bridge, the resistance of its leg wires, and the insulation of its current-carrying parts. The proper layout of a circuit where a number of shots are to be fired simultaneously depends not only on the types of detonators that are used and their arrangement and interconnections, but also on the size and insulation of the wire leading back to the source of power, and even on the source of power itself. Various types of electric shot-firing machines have been developed, and these offer still another field for study. In investigations of electric detonators and electric blasting equipment, the oscillograph is valuable because it can record electrical activity over very short intervals of time. By its use more complete information about electrical performance can be obtained than by any other means.

Jan 1, 1926

By C. W., Davie

"DEFINITIONDiatomaceous earth consists almost entirely of the silicious remains of minute flowerless aquatic plants known as diatoms. The name diatomaceous earth, therefore, is to be preferred to others such as trade names, inappropriate terms, or names correctly applied to some other product. The following names should, therefore, not be used for diatomaceous earth,-- kieselguhr, infusorial earth, diatomite, celite, moler, bergnehl, English rottenstone, tripoli, tripolite, fossil earth, desmid earth, white peat, tellurine, randanite, ceyssatite, or any trade name.FORMATIONDiatoms live in practically all kinds of water, fresh or salt, hot or cold, still or running and under different conditions of depth and pressure. These minute plants assimilate inorganic salts from their environment and produce skeletons of silica much as mollusks secrete lime and form their Shalls. When the diatoms die they settle to the bottom together with anything else which may be present, such as sand, clay or volcanic ash. The organic matter gradually disappears leaving the silicious skeletons of the diatoms which, with impurities, make up the deposits of diatomaceous earth. These deposits which are still being foamed at the present time and which were produced throughout very different epochs, were more prolifically formed in the Tertiary, so that the thickest beds so far discovered are of that Age."

Nov 1, 1925

By C. H. Kats, E. G. Meiter, J. J. Bloomfield

"INTRODUCTION.Street manholes for underground power and signal circuits, and for sewers vary in size from small openings that a workman can enter, to large central vaults. As the gas hazards in manholes are similar to those in mines, the mine safety committee of the Bureau of Mines was asked whether the miners' flame safety lamp is a practicable device for indicating inflammable gases in manholes.The coal miner detects firedamp (methane or CH4) with his flame safety lamp by observing the luminous can or the increased length of flame that appears when 1.5 per cent or more of the combustible gas is present. The lamp flame also warns him of lack of oxygen by going out when the oxygen becomes less than 16 to L7 per cent. A tentative rule regarding the proposed use of safety lamps at manholes has been suggested previously as follows: ""Testing for gas: Do not enter manholes until you have .assured yourself that the manholes are free from dangerous gases, by testing with an approved safety lamp, by ventilation, or by other adequate methods."" The Bureau's committee recommended that miners' flame safety lamps are not suitable,testing in manholes because hydrogen gas may be formed therein. The flame safety lamps approved by the Bureau of Mines for use in aseous mines are safe in presence of methane and while not tested against the members of the paraffin hydrocarbon series (CnH2n+2) higher than methane they been have been used therein; the lamps should not be used in hydrogen or acetylene they can initiate explosions in presence of these gases."

Oct 1, 1925

By Ernest A. Hersam

"INTRODUCTION.Luring the year 1923 a complete survey was made of the condition of research in the reduction (milling) and concentration of ores and nonmetallic minerals - that is, up to the stage where the ores or concentrates were ready for hydro- or pyro-metallurgical treatment. This survey was carried on under the general supervision of L. A. Lyon, assistant director and chief metallurgist of the Bureau of mines, in cooperation with the milling committee of the American Institute of mining and metallurgical Engineers, the Massachusetts Institute of Technology, and the University of California. Other institutions, including the National Research council, were of assistance and outlined recommendations during the study.While this report is on ""ore dressing"", it contains short sections on coal and clay. The mechanical handling that these minerals undergo is ""dressing"", so that ore dressing is inclusive of metallic and nonmetallic minerals. ""milling"", in its broadest sense, includes with ore dressing certain other metallurgical treatment which the report is not designed to cover.The survey revealed that considerable experimentation is being carried on great cost to the mining industry, but that the research is in general poorly coordinated while companies and firms are adequately taking care of routine tests and the mechanical features involved in their own operations, no comprehensive study of the fundamental principles of ore reduction is now in progress or contemplated. Many industries, besides mining, are interested in the preparation of materials for final treatment, rendering this investigation of value also to them. This class of fundamental research is neglected by industry unless there is some agency which can bring together at least a majority of this interested in a cooperative effort. It can not be effectively handled by a single company; and, moreover, no company can be expected to bear the whole burden of an investigation to benefit the entire industry or a number of industries hence there is need for concerted study within reasonable limits. Furthermore, co-operation eliminates duplication, which is largely a waste of effort and capital."

Mar 1, 1925

By A. C. Watts

FOR several years, a mine in Colorado experienced considerable trouble from small fires caused by the blasting of coal. Although a well-known make of permissible powder was used, it was first thought that the powder ignited gas that might be present and that this, in turn, set fire to line brattices or to the coal. Experiments were, therefore, conducted with another make of powder, but the results convinced the superintendent of the mine, Robt. Williams, Jr., that the fires were not caused by the powder but by the high-voltage electric current used for detonating the shots. The mine "makes" gas very freely, giving off from three-fourths to a million cubic feet of methane per 24 hours. The coal is a good grade bituminous of a very free burning quality. Electric shot-firing from the outside after all men and animals were outside had been practiced for a number of years. The shooting circuit was connected with the main power circuit at the mouth of each entry. Shooting circuit switches were mounted in boxes, which were kept locked with the handle of the switch, in open position, showing through the bottom of the box. The door of the box could not be shut and locked when the shooting switch was closed. At the entrance to each room, or working place, a small switch, called the miner's switch, was placed on the shooting line. It was the duty of the miner, when entering his place at the beginning of the shift, to see that this switch was open and that it was kept open until he left the place at the end of the shift to go out of the mine. Grounded return was used for main power lines. The current was 500 volts, direct current, with 100 to 300 amp. The nearest working face was 9600 ft. from the shot-firers' switch outside the mine and the most remote working face was 2 ½ miles. The various working faces were scattered over a wide area between these two points.

Jan 9, 1925

By D. Harrington

FROM 1870 to date, the coal production of Utah has been somewhat less than 85,000,000 tons. There have been at least three major disasters with total fatalities about 380; or approximately. 4.4 persons killed by mine explosions per million tons produced, a record that is decidedly bad. Even during the periods when there have been no disasters, such as the years 1914 to 1920, inclusive, the fatalities .in ordinary working ran about 5.4 per million tons produced, against 3.7 per, million tons. for the whole United States for the same years. The five-year period following the war, 1918 to 1922 inclusive, showed 4.7 fatalities per million tons, hence the fatality record in the coal mines of Utah has uniformly been in excess of the average of the coal mines of the entire country. Notwithstanding this poor record, Utah has given to the coal-mining world many excellent safety methods and practices and the Utah. coal mines in general take greater measures toward safe mining than do the coal mines of any other State; if practices and methods allowed and pursued in coal mines of other States were tried in Utah coal mines, there would be a succession of disasters. Utah's principal producing coal mines, operated by about eighteen companies and numbering less than forty, have comparatively thick seams. Very little coal under 5 ft. thick is being worked and practically none under 4 ft.; much, if not most, of the coal comes from seams in excess of 8 ft., some running as high as 30 ft. In thick seams in which coal is left on floor and roof, any dust found or made is entirely combustible. In addition, the thick seams induce the use of large capacity cars, handling which in rooms and other workings on fairly heavy grades (up to 10 or .12 per cent.) tends to cause haulage accidents. The thick seams give high ribs and roof, in which it is difficult to prevent slabs of coal or rock from dropping on workers and also difficult to keep free of gas and of coal dust. The coal is high volatile, running usually over 40 per cent and in some instances nearly to 50 per cent; hence is highly flammable. Most of the coals have very high resin content, the resin usually being in dust form, hence almost as highly flammable as black powder. At .least one-third of the mines give off methane and several give off other

Jan 8, 1925

By W. T. Jr. Thom

IN PREVIOUS classifications of coal, it has been customary to regard moisture eliminated from coal samples between 20° and 100° C. as extraneous matter, rather than as a constituent part of the coal. It seems, however, that the physical character and use properties of the low-rank coals are directly related to the amount of such moisture present, and recent chemical work has shown1 that such coals contain unstable groupings which decompose between 20° C. and temperatures somewhat above 100° C., with the splitting off of moisture. According to this view, the moisture eliminated from air-dried coal below boiling point is similar in all essential respects to moisture eliminated above 100° C., and is produced by analogous reactions; and inasmuch as the moisture given off above 100° C. has always been treated as a constituent of the volatile matter of coal, it would seem that consistent usage would include as a part of the volatile matter all moisture present as an essential component of the coal as it occurs in nature. As a matter of experience, it seems clear that the general physical and chemical characteristics of the low-rank coals are largely determined by or related to the moisture, whether chemically or physically combined, present in air-dried coal; it is also demonstrable by trial that the low-rank coals cannot be satisfactorily classified on a purely chemical basis by using the moisture free form of analysis. The low-rank coals of the western United States include numerous well-defined types, many of which were referred to in a classification proposed by Ashley,2 in which the physical and use properties of the coals were made the primary basis for their systematic grouping. When testing this classification by replotting analyses of these type coals according to the Seyler scheme of classification,3 a satisfactory parallelism between use properties and chemical constitution of the dry coal was found among

Jan 5, 1925

By J. Jolly

THIS short note on the probable character of the organic sulfur compounds in coal can do no more than indicate lines of research. We have no new experimental work to describe, nothing comparable in value with the careful studies of American coals by Powell and Parr1 and Yancey and Frazer.2 A study of the manner in which sulfur compounds exist in British coals (and their behavior on heat treatment) is rendered increasingly necessary by the fact that the British reserves of good coking coals of reasonably low sulfur content are fast being depleted. We believe that it is essentially by a study of the modes of formation, occurrence, and decomposition of the various types of inorganic and organic sulfur compounds in coal that it will be possible, with hope of success, to attack the problem of purifying coals, otherwise eminently suitable for coking, from these objectionable ingredients. Sulfur, so far as is at present known, does not normally occur in the free state in the coal conglomerate, but is chiefly distributed, irregularly, in three forms: 1. As primary constituents of the coal conglomerate, organic in nature and probably associated with those molecular complexes that have resulted from the degradation of the proteins of the plant tissues responsible for the formation of the coal mass. These constituents can be classed as "organic sulfur." 2. As metallic sulfides, e.g., iron pyrites. 3. As metallic sulfates, e.g., calcium sulfate and ferrous sulfate. (The occurrence of these compounds varies with the occurrence and degree of degradation of class 2.)

Jan 3, 1925

By C. H. Jr. Herty

IT Is well known that manganese will desulfurize molten iron through the formation of manganese sulfide, which, being only slightly soluble in the metal, rises to and enters the slag where it remains as such (mixer slag) or is converted partly or wholly to calcium sulfide (basic open¬hearth slag). The reaction by which manganese sulfide is formed is Mn + FeS = MnS + Fe. This reaction is generally considered to be reversible, although McCance1 states- that such is not the case. The experimental work was carried out to confirm the results of Rohl2 as to the reversibility of the reaction. Six trials are herein considered. In each 200 grams of electrolytic iron free from manganese and sulfur were melted in a pure zirconia crucible in a carbon resistance electric furnace. To the melted iron in runs 2, 3 and 4 metallic manganese and manganese sulfide were added to give 1, 2 and 4 per cent. manganese respectively, with 0.50 per cent. of sulfur in each. In runs 5, 6 and 7, metallic manganese andiron sulfide to give the same proportions of manganese and sulphur as in runs 2, 3 and 4, were added. The melts were held molten in the furnace for an hour and then cast into small ingots.

Jan 2, 1925