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By Yap Chu-Phay

ALTHOUGH chronologically, the Sb-Bi system was the first one studied by the writer, the theoretical basis of the equations used in this paper is fully discussed in the writer's paper on the iron-carbon system,1 because he believed that many would be more interested in the iron-carbon alloys. He suggests, therefore, that the reader consult that paper to familiarize himself with the theoretical aspect of the thermodynamic treatment outlined herein. This paper is divided into two parts: Part I deals with the Sb-Bi system and Part II deals with the lead-rich side of the Sb-Pb system. Although the former system has not much practical interest now, it has great theoretical interest in that it, is the one system that for a long time was thought to have (and under specific conditions still has) an anomalous solidus, which no amount of physical investigation could adequately account -for. The latter system of course, is particularly interesting in the lead-rich end. It will be shown that the thermodynamic method is capable of predicting reliably the equilibrium position of the solidus, and thus acts as a check on the experimentally derived solidus.

Jan 1, 1931

By H. S. Martin

THE Phosphate Recovery Corporation operates three flotation plants, Nos. 1 and 2 concentrators about three miles northeast of Mulberry, Florida, and No. 3 plant at Wales, Tennessee. These plants represent the first commercial phosphate flotation operation and are also believed to be the largest nonmetallic flotation operation in the world at the pres-ent time. The details of this paper will be confined to plant No. 2, this being the newest and largest concentrator in Florida, and the flow sheet being practically the same as at plant No. 1. The No. 3 plant has been oper-ated but a short time and has been shut down since December, 1932, on account of the decrease in phosphate rock production. The phosphate washers usually are located centrally on a known deposit so that about two hundred acres of ground can be mined eco-nomically to each washer location. The washers are moved to new areas when the distance becomes too great for economical pumping. The flotation plants are built either adjacent to a washer, so that current debris may be utilized, or on the site of a former washer where there is sufficient accumulated debris available for mining, and the flotation plants must also be moved from time to time. Most of the water used in the Florida flotation plants is recovered after passing through a circulating system where most of the fine sus-pended matter is settled out, but some make-up water is obtained from deep wells near the plant. Power is obtained from the Tampa Electric Co. through the dis-tribution facilities of the International Agricultural Corporation. Flotation concentrate is hauled from the plant by trolley over the International Agricultural Corporation's trolley system, to the drying plant at Prairie, one mile northwest of Mulberry.

Jan 1, 1933

By John Dodd

This paper reviews advances in the technology of abrasion resistant iron and steels, which could help combat abrasion and wear in mining operations. With the recent progress in high chromium alloy iron development, high temperature heat treatment of massive castings can be eliminated, aloy cost reduced, and cracking problems avoided. Data on erosion-corrosion resistance of these irons; trends in the development of improved cast steels; and factors influencing toughness and abrasion resistance of manganese steels are all considered. The 7% Mn. 1% Mo manganese steels are shown to combine toughness and abrasion resistance, and composite castings are a means of combating abrasion in applications involving severe impact. A brief appraisal is given of recently developed martensitic wrought steels with improved weldability.

Jan 1, 1982

By H. S. Drinker

I. The Mines THE first discovery of zinc on the property now worked by this company was made by the celebrated mineralogist, Prof. William Theodore Röpper, in 1845. Different claimants kept the property in continual litigation till 1861, when everything was satisfactorily settled by the purchase of the land by the company, who have worked it ever since. The mines are situated in a valley, four miles south of Bethlehem, Pa., in Lehigh County. The valley is from two to three miles broad, and is bounded on the north and south by syenitic hills. Syenite underlies the valley, and upon this is deposited the Potsdam sandstone, then a layer of slate, and, finally, a dolomitic limestone, belonging to the Chazy or Black River formation, in which the zinc deposits are inclosed. The rocks occur in folds, and have evidently been subjected to tremendous pressure from below, the zinc deposit being found in an anticlinal axis, in nearly vertical veins. It is supposed that the zinc was originally disseminated through the

Jan 1, 1873

By A. D. Hodges

The great mining region of Peru is a mountainous belt of country, running nearly the whole length of the republic, and comprising the two grand ranges of the Andes with the elevated table-lands between them. On the east of this belt are the extensive plains and fertile valleys of the Amazon and its tributaries. On the west is a narrow strip of coast 20 to 50 miles wide, for the most part a sandy desert, but producing abundant crops where irrigated ; and here are found petroleum (Department of Piura), salt (at Huacho and elsewhere), nitrate of soda in enormous amounts at the south, silver in a few localities (Province of Tarapaca), copper and other mineral products. The Western Cordillera, running nearly parallel with the shoreline, rises like a wall on the eastern side of the coast-belt, with passes from 15,000 to 18,000 feet high and peaks attaining 18,000 to 20,000 feet. Further east, at a varying distance, is the Eastern Cordillera, composed of broken mountain ranges which, considered as one group, have a general parallelism with the western chain, but individually vary greatly in direction, sometimes running nearly east and west, in places projecting out into the Amazonian lands, or here and there curving around to unite with the western ridge, and with this enclosing immense inter-alpine plains. These general features are indicated in Fig. 1. The surface of these plains is uneven and traversed by lower ranges of hills which surround large lakes, or rolling pampas, or fertile valleys; and through many of these last run rivers of considerable size. The whole country has a high altitude (averaging up to 15,000 or 16,000 feet), and slopes gradually north and east towards the Amazon, into which drain all its waters. Its bounding mountain chains are scored on all sides by narrow, picturesque and pre-

Jan 1, 1888

By Arthur R. Kommel, Robert F. Mehl, Gerhard Derge

The orientation relationships resulting from allotropic transformations and the formation of segregate structures in metals and alloys have been the subject of the eight earlier papers in this series'. A brief summary of orientation studies has also been given by Sachs2. A survey of these papers discloses that the factors that determine the orientation relationship of a precipitated phase to its parent solid solution, as well as the outward form and appearance of the new phase, are not completely understood. It is now evident that crystallographically analogous systems, as a rule, exhibit the same type of Widmanstatten figure and orientation relations, so that useful information is not to be expected from examination of a new alloy involving lattice combinations of which the orientation relationships are already known. Therefore, the determination of the relations existing between lattice types that have not already been studied seems to be the most promising mode of attack upon the problem; both of the systems reported in this paper represent new combinations of lattice types. A. The Mg-Mg2Sn System The magnesium-tin equilibrium diagram given by Hansen3 shows the phase Mg2Sn to be the only intermediate phase. The solid solubility of Sn in Mg decreases from 14.8 weight per cent at the eutectic temperature, 561' C., to 2.3 per cent at 450°, while no solid solubility of Mg in Mg2Sn has been observed. The crystal structur: of Mg is close-packed hexagonal with a0 = 3.202 A. and co = 5.199 A.4, while Mg2Sn is of the CaF2 type with a. = 6.78 A., with four molecules in a unit ce115,6. Alloys from two different sources have been used: (1) those supplied by the Dow Chemical Co., which contain 6 and 8 weight per cent Sn, and (2) those prepared in this laboratory, containing 8 and 13.5 per cent Sn. The latter were made from Dow high-purity Mg and Baker chemically

Jan 1, 1937

By F. H. Daniels

IN this, paper it is my intention to, call your attention to* a few of the many producers using blast, now, in common use in Sweden, and also those constructed by the Washburn & Moen Manufacturing Company at their Quinsigamond Works. During a prolonged stay in Sweden the writer had an opportunity

Jan 1, 1881

Discussion of the paper of EDWARD G. NORTON, presented at the New York meeting, February, 1915, and printed in Bulletin No. 97, January, 1915, pp. 93 to 102. G. D. HARRIS, Ithaca, N. Y. (communication to the Secretary *).¬Since I have on several occasions1 expressed at length my general views on this interesting subject, it seems fitting that I endeavor here to comment as briefly as possible on a few points suggested by the paper. Doubtless you all know of the rather extensive publications of Lachmann on mid-European salines and his scarcely successful, attempt to make the phenomena presented by our domes fit. into his "Exzeme" theory based on studies of European phenomena. This paper is a most welcome indication that scientific America is very much alive to the difficulties that have been encountered in attempts already made to explain the origin of the salt domes in the lower Mississippi embayment region. Praiseworthy, too, is the attempt to explain these phenomena by agencies still in operation. I may, perhaps, be permitted to state here that a former student of mine, and co-worker in Louisiana, A. C. Veatch, is now interested in the Algerian region, where it would seem similar dome-phenomena are to be found, and hopes may well

Jan 5, 1915

By George M. Fowler, R. E. Illidge

Part I. Developing BY GEORGE M. FOWL INTRODUCTION The Tri-State district comprises an area of about 2000 square miles in southwestern Missouri, southeastern Kansas, and north [ ] eastern Oklahoma. The part that is in and contiguous to Missouri is still sometimes designated as the Joplin district (Fig. I). EARLY OPERATIONS Mining operations in what is now the Tri-State district date from about 1848 and have been continuous to the present. Apparently the first discoveries of ore were made about the same time near the present sites of Joplin, Oronogo, and Granby. Lead minerals were found at grass roots, probably in shattered rock in shallow excavations, then these minerals were followed in shear zones to deeper horizons. The mining of zinc followed. Before 1874, zinc ore was worthless and discarded as waste. According to published records, the total production of lead to that date was 49,000 tons of metal from 70,000 tons of concentrates. PRODUCTION The aggregate ore production from the Tri-State district was recorded at interval

Jan 1, 1943

By M. J. Taylor

A common method of classifying non-water- impounding mine waste structures is necessary to facilitate professional comnunications within the industry and between representatives of industry and government. Camnon classifications can a1 so he1 p quickly create and maintain a mental picture of the structures being discussed. Three categories for classification presented in this paper include: (1) configuration and location with respect to existing topography. (2) material characteristics of waste, and (3) environmental sensitivity or characteristic; of the disposal area. Configuration and location classification involve terminologies typically utilized for waste dumps over the past several years. General classification categories for non-impounding structures include: (a) valley-fill, (b) cross-valley, (c) side-hill, (d) ridge, and (e) heaped. Material characteristics can govern the location, engineering details, and environmental sensitivity of the waste structure. Material classification includes: (a) hazardous, (b) non-hazardous, (c) inert, (d) fugitive dust susceptible and (e) leachate susceptible. A1 though many characteristics are potentially applicable, this paper will focus on the categories mentioned above. Environmental sensitivity of a waste structure encompasses many objective and subjective evaluations plus many multi-disciplinary considerations. Environmental sensitivity incorporates numerous factors in addition to those highlighted in configuration and location, and material characteristic classifications. A few examples of how this categorization can govern the engineering design and location of waste dumps are provided in this paper. In addition to the verbal descriptions of classifications, a simplified version of the combined classifications with an alphanumeric format and its methodology is discussed in this paper. Surface water controls often govern the classification or vice versa. In order to maintain a non- impounding status, water must be prevented from collecting behind the structures. Depending on material characteristics, water inflow to or over the site can cause significant environmental or human consequences. Finally, the access of water to the waste dumps can play a large role in the degree of environmental sensitivity to the site. This paper provides a framework in which to discuss the other aspects of this conference and also provides insights as to how the framework is based on actual practice.

Jan 1, 1985

By Christopher Haycocks, Michael Karmis, David G. Lundy

Roof bolting is the most common means of support in under- ground coal mines. The main advantages of this support system are the relative ease of installation and the ability to provide a stable and unobstructed work area. Roof bolts can be broadly classified into two categories, mechanical and resin bolts. Currently, about 20% of all bolts used are the resin types, and trends show an increasing popularity of these kinds. Although the reinforcing effects of resin bolts have been well demonstrated, there is, nevertheless, a considerable lack of knowledge of their interaction with the surrounding strata. To study this interaction and to further investigate the mechanisms involved in resin bolting, an instrumentation system was designed and tested in a southwestern Virginia coal mine. The instrumentation system was composed of straingaged resin bolts, convergence and differential sag stations, and a borescope. Strain gages mounted on the bolt determined axial, bending, and shear strain at several levels along the axis of the bolt. The roof movement, as measured by the convergence and differential sag readings and as observed by the borescope, correlated well with the strains registered on the bolts.

Jan 1, 1983

THE CHAIRMAN (J. W. MALCOLMSON, Kansas City, Mo.).-Gentlemen, Dr. P. J. O'Gara, Director of the Department of Agricultural and Smelter By-Products Investigations, of the American Smelting & Refining Co., Salt Lake City, Utah, is here; he has given attention to this very important problem and I will call on him for a few remarks. P. J. O'GARA, Salt Lake City, Utah.-I have had charge of the investigations of the smoke problem for the American Smelting and Refining Co. during the past four years. One of the worst burns we ever experienced occurred shortly after we began putting all our gases through the baghouse. This occurred in 1914 after the roaster gases had been put through the baghouse; previous to that time, the greater portion of the roaster gases was not put through the baghouse. Everyone knows why a hot-air balloon goes up. The hotter the air in the balloon, the higher it will go. In other words, hot gases will rise higher than cold gases. When gases are handled in any way that will tend to lower their temperatures, these gases are going to travel less high in the atmosphere and will therefore tend to reach the ground sooner than if they are turned out very hot. So far as injury to vegetable life is concerned, sulphur dioxide is the only element in smelter smoke that need be considered. The solution of the problem will be either to take out the excess of sulphur dioxide or to diffuse it high enough, up in the atmosphere so that the concentra-

Jan 1, 1918

By R. F. Mehl, R. W. Parcel

THE rate of the decomposition of austenite in eutectoid steels, forming only pearlite, may be expressed fundamentally in terms of the rate of nucleation and the rate of growth of pearlite nodules. This matter has received much attention in recent years. (The basic references are listed in ref. 1; references of particular import to the present work will be given separately.) Systematic data have been developed for plain carbon eutectoid steels.:! Although the physical factors affecting the rate of nucleation, N, in case of plain carbon steels have presumably been identified, they cannot as yet be evaluated quantitatively.' Several somewhat successful attempts, however, have been made to calculate the rate of growth, G. In the latter case the important factors determining the edgewise growth of pearlite have been assumed to be: 1—the interlamellar spacing; 2—the concentration extremes and concentration contours of carbon in austenite in front of the growing pearlite interface; and 3—the rate of diffusion of carbon in austenite.* The only systematic data on N and G for pearlite in alloy eutectoid steels are those for Co-steels;6 there are no data on alloy eutectoid steels in which the alloying element is known to decrease the rate of formation of pearlite, apart from a few scattering data reported earlier' for steels containing manganese. This paper reports a systematic study of N and G for eutectoid alloy steels containing molybdenum and nickel, respectively. In order to provide information of help in understanding the results, new data are presented on the effect of molybdenum on the interlamellar spacing of pearlite, So; data on the effect of nickel on So have already been published.' The alloys used were in five groups: 1—Pure Fe-C-Mo alloys (Table I) were supplied by the Climax Molybdenum Company of Michigan, Detroit. They were made from Armco ingot iron of standard analysis, Acheson graphite, and ferro-molybdenum, melted in silica-lined crucibles in a high frequency induction furnace. The ferromolyb-denum was added to the melted steel, followed in 5 min by 0.08 pct Al. The ingot as-cast measured 23/4x 31/4x10 in.; it was hot-forged at 1150°C to a bar 1 in. sq.

Jan 1, 1953

By Paul L. Russell

THIS is a progress report of an experiment being undertaken in cooperation with the Bethlehem Steel Corp., the Crucible Steel Co., and the Rock Bit Sales and Service Co., involving heat treatment of the shank ends of drill steel. This experiment is being conducted by the U. S. Bureau of Mines in its experimental mine, Mining Research Branch, Bluemont, Va. The purpose of the experiment is to determine the effect of an increase in the time the steel soaks in the furnace during the hardening heat. It has been thought that increasing this time produces a soft zone below the lugs resulting in a metallurgical notch that causes early failure. Each of the steel companies furnished enough 11/4 - in. straight carbon, hollow, round steel to make up 10 sets of drill steel, in each instance the steel bars were from the same heat. These sets of drill steel, consisting of 2-ft, 4-ft, 6-ft, and 8-ft lengths were fabricated by the Rock Bit Sales and Service Co. Special attention was given to the forging of the steel to produce the best rods possible. The heat treatment of all thread ends was identical and followed the best practice. The heat treatment of the shank ends of five sets of steel from each company produced a soft zone 2 to 4 in. in front of the lugs. It was decided that possibly the best way to obtain this effect was not to overlap the hardening heat but to let the steel soak for an additional 30 min before quenching. Therefore the only variable in the test steels is the length of time the shank ends were in the furnace. The remaining drill steel shanks were treated as follows: Heat treatment in pyrometer-controlled furnace at 1550°F. Quenching oil at 105°F to 125°F temperature. Areas for heat treatment were; shanks, 11 in.; threads, 9 in. Time at heat, standard practice, 20 min for 11/4-in. steel. Actual drilling tests were made in greenstone, (a metamorphosed basaltic rock), and in epidosite. Greenstone has a specific gravity of 2.96 and a compressive strength of 44,200 psi. Epidosite has a specific gravity of 3.26 and a compressive strength of 63,100 psi. All drilling tests were made using a 31/2-in. column-mounted, automatic feed drifter, with a controlled air pressure of 90 psi at the throttle. Tungsten-carbide bits of 2 in. diameter were used for all drilling. Contrary to expectations the drill steels that were allowed to soak for the additional 30 min before quenching performed better than the steels that were heat treated according to standard practice. This performance, as shown in Table I, was especially noticeable in the drilling of epidosite. The "longheat" drill steels furnished by Company "A" drilled 154 pct more minutes than the "standard-heat" steel. Expressed in feet, the "long-heat" steel drilled 114.60 ft more before failure than the "standard-heat" steel. The "long-heat" steel furnished by Company "B" drilled 37 pet more minutes or 60.39 ft more before failure than the "standard-heat" drill steel. The effect of the long heat treatment was not as evident when the steels were drilling in greenstone (Table II). In greenstone, the increase in minutes drilled by the "long-heat" steel over the "standard-heat" steel was 47 pet and 1 pet, respectively, for Companies "A" and "B."

Jan 1, 1952

By G. Thodos, E. M. Phillips

A reduced density correlation for the gaseous and liquid regions of ethane has been developed from all the experimental PVT data available in the literature for this substance. Saturated vapor and liquid densities reported for methane, propane and n-butane were utilized to establish the rectilinear-diameter line for ethane. This line was then used with the saturated-vapor data for ethane to produce the saturated envelope for this substance. Most of the saturated liquid data reported for ethane were found to be inconsistent with the saturated-liquid curve resulting from this study. The correlation covers the regions 0.65 < TR <6.0 and 0 < PR < 15. For regions for which no experimental data have been reported, the isobars of the correlation were extended by the use of the theorem of corresponding states. This correlation is presented both on rectilinear and log-log coordinates. INTRODUCTION At the present time, there is considerable interest in the exact PVT behavior of pure hydrocarbons. Matschke and Thodos12 recently have developed a comprehensive compilation of experimental vapor and liquid density data for methane. Similar studies have been conducted for other pure substances.4, 7 In the present study the density data available in the literature for gaseous and liquid ethane have been critically reviewed and utilized to develop a reduced density correlation for this substance. SATURATED LIQUID AND VAPOR DENSITIES The rectilinear-diameter rule proposed by Cailletet and Mathias5 states that the sum of the saturated liquid and vapor densities of a pure substance is a linear function of temperature which passes through the critical point. This law, although empirical, has been well established by continued verification since its conception in 1886. This rule has been applied to the saturated density data of methane,6 propane 17 and n-butane8 to produce the straight lines presented in Fig. 1 which pass through the critical point TR = 1.00, Pr = 2.00. The rectilinear-diameter relationship for ethane was established from the lines for the other substances in Fig. 1 by plotting the quantity p~, + PR against zc for different reduced temperatures. A critical analysis of the saturated vapor and liquid densities reported for ethane by Kuenen,10 Maass and McIntosh,11 and Sage, Webster and Lacey18 revealed that the values of PR1 + pr resulting from these studies were inconsistent with the rectilinear-diameter line obtained from the reliable density data of the other substances, as shown in Fig. 1. In the analysis of these data, reduced quantities were calculated using the critical con-

By John A. Hosking

The recent activity of numerous foreign mining companies in the once flourishing tin fields in Cornwall, England has resulted in renewed interest in the evaluation of hypothermal tin deposits. These deposits are mainly narrow tabular bodies and are usually steeply dipping. They exhibit thermal zoning the mineralization changing from lead/zinc through copper to tin with depth. The tin zone virtually never exceeds 1,000&apos; in depth and the ore shoots within this zone tend to be erratic and localized. The grade which is presently considered to be economic is about 0.7% Sn. , this means a concentration of about l% cassiterite (the only economic mineral) which, being twice as heavy as the gange, represents only. 5% of the lode volumetrically. Within the lode, only one third may reach this economic grade and values within the shoots can range from 100% cassiterite to zero over a few inches. The enormity of the problem of evaluating such a deposit has not been fully appreciated by the companies involved whose experience has, for the main part, been in larger and more predictable ore bodies. This paper attempts to put these problems into perspective and out- lines the useful applicatations of statistical and computer techniques. It also stresses the need for enlightened interpretation of data by men familiar with the problem and that even in this day and age, educated, intuitive deduction should not yet be relegated to the limbo of alchemy and witchcraft.

Jan 1, 1969

By M. T. Simnad, C. E. Birchenall, M. H. Davis

The transport mechanisms previously proposed in wustite and hematite have been confirmed by movement of inert markers during the growth of these phases. By similar measurements the mechanism for magnetite has been determined. The rates of growth of multilayer scales on iron, magnetite and hematite on wustite, and hematite on magnetite have been measured. All rates are found to be diffusion controlled under the conditions of the experiments. MANY studies have been made of the rate of oxidation of iron in both the low temperature, film-forming region and the high temperature scaling range. The interpretation of the results has been greatly complicated by the formation of multi-layered scales containing the various phases of iron oxides. In most cases no attempt has been made to determine the composition of the scale and its dependence on time of oxidation in a quantitative manner. However, several recent studies&apos;" have taken this variable into account. It is generally agreed that the growth of thick scales on iron follows a parabolic rate law for the increase of total thickness. In the thin film region agreement has been claimed with parabolic equations of various forms and with logarithmic equations. The discussion here will be concerned only with the formation of scales of considerable thickness, greater than several microns, although some of the conclusions may be applicable to thin films. A brief survey will be given of the solid phases of the iron-oxygen system, the stability of wiistite in bulk and in thin films, the relative densities of iron in the metal and oxides, and the kinetics of forma- tion of oxide scales on iron. New experimental results will be introduced at several points during the discussion, and an attempt will be made to formulate a mechanistic picture consistent with these observations. The experimental techniques are described in an appendix. Iron-Oxygen System Fig. la shows the iron-oxygen phase diagram. Wüstite ("FeO"): The lowest of the oxides has a NaCl type cubic lattice formed by close-packing of the relatively large oxide ions with the smaller iron ions arranged in the interstices. The ionic radius for 0&apos; is about 1.3 A, while Fe++ has a radius of about 0.8A and Fe"&apos; about 0.7A. Its range of existence on the phase diagram is very wide for an ionic material of this type and does not seem to include the stoi-chiometric composition FeO. These deviations appear to be well established as vacancies on iron lattice sites by the comparison of lattice parameters and densities for a series of compositions by Jette and Foote.4 The limits of the field are disputed, but the work which seems most reliable" indicates vacancies in from 5 pct to more than 12 pct of the iron sites. In order for the crystal to be electrically neutral, there must be electron holes which correspond to the formation of trivalent iron ions equal to twice the number of vacancies. Magnetite ("Fe³O4"): Considerable disagreement also exists in the literature about the stable range of the Fe³O4 field. Some diagrams show the Fe³O4 composition to be lower in oxygen than the formula indicates, but Schenck6 gives a diagram from the

Jan 1, 1952

By C. H. Loux

THIS paper deals primarily, with the advantages realized from the adoption of methods more suitable than those previously used. The improvements noted include: (1) modification of practice in shrinkage stoping, (2) use of sublevel caving over grizzlies, (3) improved haulage and loading, (4) use of contract wages wherever possible. The Washington mine is on Jonestown Hill, one mile south of Oxford, in northwestern New Jersey. It is producing 16,000 tons of concentrates a month, which are being shipped to the Alan Wood Steel Company&apos;s furnaces at Swedeland, Pennsylvania.

Jan 1, 1933

By S. C. Oliphant, C. R. Houssiere, George H. Fancher

DRILLING mud can be an item of great expense on the Gulf Coast. In order to understand the nature of a drilling mud, it is desirable to know the composition and size of the mineral particles that are present, The supercentrifuge has been adapted to the fractionation of mud, and this paper discusses the calibration and methods of operation and control. An alignment chart has been prepared, which was found useful in this work. Typical data are included, showing the comparative reliability of the method.

Jan 1, 1942

E. O?C. Acker Truman H. Aldrich John H. Allen W. Lawrence Austin W. S. Ayres David Baker Andrew A Blair Walter M. Brodie H.H. Burden Charles Butters

Jan 1, 1936