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By S. Ando

The fatigue crack growth behavior of magnesium single crystal has been investigated, CT (compact tension) type specimens with different notch orientations were prepared. In the case of notch plane and direction are (1-210) and [10-10], fatigue crack propagates parallel to notch, From TEM observation, it is found that pyramial slips occures at the crack tip. When notch is normal to basal plane, a fatigue crack propagates [0001] and parallel to basal plane depending on stress intensity factor range, In the case of notch parallel to basal plane, a fatigue crack propagates through straight route with some {10-12} twin, Fatigue crack growth rate, da/dN of A- and B- specimen is lower than F-specimen with crack parallel to basal plane.

Jan 1, 2004

By Donald F. MacDonald

WE are living in a mineral and technological civilization. The Encyclopedia Britannica defines civilization as follows: "It is the final test of a progressive civilization that a given effort shall produce a larger modicum of average individual comfort, and the pursuit of this ideal has been from first to last the impelling force which drives civilization onward". This "individual comfort" demands labour-saving machines and devices such as motor cars, radios, and thousands of other inventions, most of which require minerals and metals in vast quantity for their manufacture. In fact, more minerals and fuels have been used in the last third of a century than in all previous world history. Since 1800, the world's production of metals has increased more than a hundred fold (1). Scientific discovery is now advancing on a wide front, thanks to the research work that is being carried on in progressive countries. The world's work is now being done with very much less human drudgery than in the past. We do not have to toil for our living as our ancestors did, even if we follow their occupations. The average man has had many years added to his life-span, but, apparently, little to his spiritual stature and less to his common sense.

Jan 1, 1939

By Mario Gerards, Axel Wellendorf, Arulnesan Rajesh

"In times of increasing energy cost and global demand for improved machine technology, the optimization of industrial mineral processes in terms of efficiency and production cost is an important factor when choosing industrial equipment suppliers. Of course this applies for screening machines, feeders and distributers as well!Besides of the ability of a screening machine for being adjustable to changing requirements during the production process itself, it becomes more and more important to choose the correct screening machine type, peripheral equipment for arising screening tasks and to optimize the overall design of the screening machine starting at a very early stage.The different types of screening machines bring many advantages and disadvantages with them. The selection of the correct type of screening machine can improve the flow rate, energy, efficiency, yield, quality, output, availability and decrease the maintenance costs and structural steel work.The machine optimization has to be a consecutive process in which at any time results of simulation and “real-life measurement” are compared and the findings are implemented in machine development and design. As an example, it is possible to reduce machine weight and reinforce the steel structure of a screening machine at the same time, which enables the manufacturer to use smaller drives for the screen.This paper will present the methods ANSYS and 3D Solid Works used at RHEWUM GmbH for this way of optimizing machine design and construction and examples for results gained from this continuous improvement process."

Jan 1, 2016

By J. M. Newell, G. R. Peatfield

"The Red-Chris porphyry Cu-Au deposit is located between Ealue and Kluea lakes, southeast of the village of Iskut on the Stewart Cassiar highway in northwestern British Columbia. It was explored by Texasgulf Inc., in a joint venture with Great Plains Development Company of Canada, Ltd. and Silver Standard Mines Ltd., during the period 1973 to 1980. Exploration resumed in 1994, following acquisition of the interests originally held by Texasgulf and Great Plains Development by American Bullion Minerals Ltd.Prospectors were first drawn to the area by prominent limonitic stain zones exposed in creek gullies in the western part of the property. These zones are developed on the alteration halo at the western periphery of the deposit. The potential ore zones do not crop out and were first exposed in a bulldozer trench excavated in 1971. Subsequent exploration was by percussion and diamond drilling, guided to some extent by induced polarization surveys. In 1976, estimated resources contained within two crudely designed open pits were 41 million tonnes with an average grade of 0.56% Cu and 0.34 g/t Au, with a cutoff grade of0.25% Cu. New resource estimates based on a major drilling program completed by American Bullion in 1994 were released as this paper goes to press. These estimates were calculated using various copper cutoff grades; at the 0.4% Cu cutoff, the ""in-situ geological reserve"" is given as 100 million tonnes grading 0.58% Cu and 0.46 g! t Au (American Bullion Minerals Ltd., 1995).The deposit consists mainly of pyrite, chalcopyrite and increasing bornite at depth, in zones of quartz-vein stockwork hosted by an elongate body of altered monzonite porphyry of latest Triassic or earliest Jurassic age. The stock intruded volcanic and sedimentary rocks of probable Stuhini Group affinity and is in faulted contact with sedimentary rocks of the Jurassic Bowser Lake Group. Gypsum stockworks are developed in the higher levels of the subvolcanic porphyry system. Late-stage quartz-carbonate veins carry small amounts of galena and sphalerite. Complex faulting within the deposit makes drill-hole correlations difficult. Alteration assemblages include an early potassic phase, almost completely destroyed by later phyllic alteration, and surrounded by a propylitic assemblage dominated by ankeritic carbonates in altered sedimentary rocks.The deposit has characteristics of bath the alkalic and calc-alkalic classes of porphyry copper deposits. The development of quartzvein stockwork suggests a calc-alkalic affinity, but the hostrocks contain little or no free quartz, molybdenum is present in trace amounts only and gold values are significant. Copper grades vary between wide extremes with unusually high grades in some sections of the deposit. The weight of evidence available in the 1970s led us to place the Red-Chris deposit firmly in the alkalic family. The quartz-sericite alteration assemblage was attributed to breakdown of potassium feldspar in a near-surface alteration environment in which seawater may have had a significant role. These interpretalions are retained here, but preliminary conclusions from the most recent work suggest that they may require some modification."

Jan 1, 1995

By Knud Sinding

Mining firms are widely criticised for their adverse impacts on the environment. At the same time many firms in the industry devote extensive resources, both financial and managerial, to the reduction or elimination such impacts. Very considerable improvements have been made, although these are sometimes overshadowed by a few high-profile accidents, such as the occasional collapse of a cyanide-containing tailings dam. In parallel, much effort is also directed at projecting a positive environmental image, as witnessed by extensive environmental reporting, both on paper and increasingly through web-platforms. Mining projects today almost invariably involve some form of environmental protection. In industrial countries regulations in this area are extremely stringent, as is enforcement. In less well developed countries, regulation and enforcement may be weaker, but firms are in many cases and for a number of reasons committing themselves to high levels of environmental protection, even if they might get away without doing so. Research in the area of environmental performance of mining firms has so far paid much attention to concepts such as sustainability indicators and the sustainability of individual firms. Given the still raging debates about the appropriate way to determine the degree to which any given firm is sustainable (Welford 1995) as well as the usefulness of what will in the final analysis be a value judgement, anyone on the sidelines of the debate will come back to the fundamental issue, how is knowledge that a particular firm has been judged ?sustainable? going to be made use of. This issue remains unresolved, which may explain the lack of progress in formulating a useful definition of a sustainable firm The question addressed in this paper is not so much about what firms are doing on the ground or in any particular case of environmental protection, but more in the subsequent use of these efforts - and by extension - on the overall direction of corporate environmental strategy. The fundamental problem facing all mining firms is that they cannot easily benefit from unilaterally reducing their environmental impact. The firm can of course avoid liability and keep a variety of stakeholders happy and hence experience lower costs of obtaining the [input] resources they need (in a broad sense, not just minerals), but this represents only part of the opportunities available form pursuing an environmental strategy (Reinhardt 2000). The other part, which may have an enormous potential, involves the concepts of competitor management and product differentiation. The logic of keeping stakeholders happy has been most forcefully argued by Pfeffer and Salanchick (1978) who link the behaviour of firms in all domains to their ability to obtain the resources they need, at a cost that is lower than it would otherwise be (Pfeffer & Salanccik 1978). Several varieties of strategy can be included under this heading, including cost reduction and risk management. The alternative logic is to convince customers that they want to pay more for minerals supplied by mining firm X or directly attributable to mine Y, or by making all mineral users pay more. These two strategies, which may be referred to as product differentiation and competitor management, respectively (Reinhardt 2000) are related to the demand side of mineral supply, whereas cost reduction and risk management are related to the supply side. Mining firms have not pursued the demand side very much, if at all. This is probably due to the extreme difficulty of moving mineral products, bulky and unglamorous as they are, away from their

May 1, 2003

By K. Sun, S. A. Argyropoulos

The assimilation and the exothermic behavior of Zn-Zr metallic powder compacts into molten aluminum was studied by measuring simultaneously the temperatures inside at the centerline of the compact, at its surface, and inside the molten aluminum bath, as well as the net downward force acting on the compact. In addition, the exothermic behavior of these compacts was also investigated in an argon protected atmosphere. The temperature rise inside the compact increases significantly with the mass ratio of zirconium in the compact and to a lesser degree with the aluminum bath temperature. Experimental results on the recovery of these compacts in molten aluminum will also be presented.

Jan 1, 2008

By V. Budinsky

In recent years the global mining industry has addressed its social and environmental responsibilities and numerous factors have contributed to this. Corporate Social Responsibility (CSR) is an important part of mining company strategy for practical implementation of the goals of sustainability, transparency, accountablity and good relationships with stakeholders:- investors, employees and communities. A key stakeholder for all mining companies is the local community which is affected by the mining operations. Companies must identify the emerging social and environmental trends, study the interests and concerns of various communities, address their needs and maintain a positive relationship. The CSR programmes of Czech coal mining companies are focused on surrounding community initiatives and sustainable responsible business. Mining in the Czech Republic is subject to strict rules and regulations and supervised by the State Mining Authority. Mining projects undergo rigorous approval procedures which encompass all operational measures at the different planning levels ? such as public participation in the authorisation process for mining projects, the application of the Environmental Impact Assessment Directive, environmental sustainability programmes, innovative solutions and flexible options offered by the mining company. One very important part is the preparation of the mining-technology preconditions and developing the integrated planning process in which all socially and politically relevant subjects in the mining operation surroundings are included. In an in-depth debate, all stakeholders may jointly develop the concept, in accordance with democratic principles. The optimally conducted dialogue process needs broad communication bases, including setting up theme-related joint taskforces, together with good moderation and the highly qualified support of technical experts. Using a case study of Severoceske doly a.s. Chomutov (SD Company) and the Czech Coal Group ? Czech leaders in the extraction of brown coal, this paper aims to examine the community development approaches and the CSR effectiveness of large scale mining companies. This paper brings a review of CSR and other such voluntary initiatives in the mining industry's proactive steps to contribute to societal well-being in a meaningful way. Key studies are provided by the projects ? Region with Better Perspective?, ?Stop Dust for Healthy Brezno Village?, ?Clever Heads for the North? and ?Coal Safari?. CSR issues are managed throughout all stages of the mine operation and beyond, long after the mine closes (e.g. post-closure programmes of new landscape, alternatives for reclamation including generation of lakes in former surface mines, conceptualization of industrial heritage). Communities need to be given the opportunity to help themselves through participation in CSR projects rather than being recipients of financial gifts from the company. A fair balancing of interests is the basis of any successful cooperation.

Aug 1, 2013

By P. T. Craddock, H. V. Paliwal, L. K. Gurjar

The Indian cultural heritage of mining, smelting and the use of minerals and metals dates back to ancient times. Although the exact date of the commencement of such activities in India is not certain, Indians are known to have been familiar with gold, silver, copper, tin and lead and to a lesser extent with iron at least since the Vedic period (Table 1).

Jan 1, 1999

By Guoqiang Lan, Jun Song, Bin Ouyang

Rare-earth pyrochlores, commonly exhibiting anomalously low lattice thermal conductivities, are considered as promising topcoat materials for thermal barrier coatings. However the structural origin underlying their low thermal conductivities remain unclear. In the present study, we investigated the phonon properties of a group of RE pyrochlores, Ln2Zr2O7 (Ln = La, Nd, Sm, Gd) employing density functional theory and quasi harmonic approximation. Through the relaxation time approximation (RTA) with Debye model, the thermal conductivities of those RE pyrochlores were predicted, showing good agreement with experimental measurements. The low thermal conductivities of RE pyrochlores were shown to largely come from the interference between the low-lying optical branches and acoustic branches. The structural origin underlying the low-lying optical branches was then clarified.

Jan 1, 2015

By J. R. Goode

"Canada developed pioneering rare earth solvent extraction methods to recover the rare earths and thorium as by-products of uranium recovery operations in Elliot Lake, Ontario, and was a major supplier of these key elements from about 1960 until 1990. At one stage, Elliot Lake was supplying perhaps one third of the world’s yttrium as well as much of its thorium. This paper reviews the development of Canada’s early rare earth and thorium production facilities. INTRODUCTIONThe rare earths and thorium were first identified in the early 19th century but were little more than curiosities for the next century. However, in the mid-1960s the invention of rare earth-based phosphors for the cathode ray picture tube used in colour television sets launched a major demand for certain rare earths.The use of thorium as an alloying agent in aircraft and missiles grew rapidly in the late 1950s. In the same period, demand for uranium for both weapons and power production soared. Also in the late 1950s, the Elliot Lake uranium-thorium-rare earth deposits (also known as the Blind River deposits) were discovered. This conjugation of events led to uranium production in the Elliot Lake camp, quickly followed by the co-production of thorium and, later, the rare earths.Uranium production in the Elliot Lake camp continued from 1955 to 1996. Thorium was produced continuously from 1959 to 1969. Rare earths were produced, intermittently, from 1965 to 1990. Complete production records are not readily available but unquestionably Elliot Lake made a significant contribution to world thorium and the rare earth production. This paper, presented earlier in an abbreviated form (Goode, 2012), is intended to present as much of the information that is available."

Jan 1, 2012

By Edith Lafontaine

Modern underground mines operate fleets of mobile production equipment including drill jumbos, long-hole drills, load-haul-dump machines, trucks and bolters. Their availability has a substantial impact onto production cost and thus onto mine profitability. Through appropriate collection of pertinent data and information, use of adequate performance measures and their analyses, mine operators can identify the most promising and cost effective opportunities to get more from their equipment and to reduce the overall cost. This paper presents results of the study aimed to review and analyse means and measures used to quantify equipment availability and its contributing factors (reliability, maintainability and maintenance support) in several Canadian underground mines. It overviews current reporting procedures, sources, quality and quantity of the data and information collected as well as examines performance measures and their definitions used by the surveyed mines. Problems concerning data acquisition as well as meaningfulness and usefulness of the above mentioned metrics are also discussed. The paper concludes with some suggestions and recommendations concerning several aspects of equipment availability assessment. It is believed that the latter may become a more useful tool for mine operators in their efforts to reduce production cost than it seems to be the case at present.

May 1, 2007

By Christian Ottergren

"Modern crushers offer double the capacity and performance of classic models. In some cases crushers are replacing SAG circuits, the advantages being smaller investment and lower operating costs. Is Tertiary crushing replacing SAG milling as the most optimal grinding method? Does tertiary crushing achieve the same outcomes as SAG milling? This paper considers these questions and provides an assessment of the strengths of tertiary crushing in comparison to other methods. Two case studies: a Scandinavian Platinum Project, and CODELCO, are also presented.INTRODUCTIONResearch on basic parameters in crushing started at Chalmers University in 1993. The initial project has developed and now involves several related areas. Modelling in accordance with new theories has resulted in modified designs which have been implemented and shown improved performance at operating mines in Chile. Sandvik Rock Processing is a partner and a major supporter of this program. This paper will cover some of the achievements and give references to the research reports.The mining industry has for many years mainly used crushers of the traditional 7’crusher concept, with thread adjustment of the setting and with a spring or hydraulic overload system. This machine type has been the workhorse for crushing throughout the world. The explanation for the dominance of this machine is that it has a reliable mechanical design. It can be estimated that about 2000 crushers of this design are still at work.Technical development in all fields utilizes new technologies like high-strength materials, advanced control systems and more extensive use of hydraulics. This is the reason why today’s motorcars, for example, are more efficient, more reliable and more environmentally friendly than their predecessors in the 1950s. Crushers are no exception. This paper will cover experience from the latest-generation cone crushers developed by Sandvik Rock Processing.The parts in this paper related to the CODELCO ElTeniente copper mine in Chile are coauthored with responsible personnel from the operation at the mine."

Jan 1, 2004

By A. E. Moss

"IntroductionTHE WORLD-WIDE search for iron ore has been vastly accelerated during the past fifteen years .and Canada is playing a most prominent role in this prospecting boom. During this period, the search for .and development of iron ore deposits in Canada bas proven eminently successful and there is every indication that exploration will continue to be active for many years.This paper has been prepared primarily for the information of those who have bad little or no experience in iron ore exploration. For convenience, it is divided into three parts: ( 1) a brief discussion of the marketing of iron ores, with special reference to Canadian production; (2) a summary of the main features to be considered when prospecting for or evaluating a potential iron ore deposit; and (3) an outline of the methods and procedures used in the search for the direct-shipping iron ores in the Quebec•-Labrador iron ore field.The Iron Ore MarketDue to the tremendous tonnages of high-grade direct-shipping iron ore indicated in the iron ore fields of the Quebec-Labrador and Steep •Rock areas, it might be assumed that there would have been a sharp decline in iron ore prospecting in this country. On the contrary, the development of these two major fields, which must be classed among the world's greatest, has been responsible for much of the current activity. The search for high and medium grade magnetite deposits is being• conducted in many parts of the country and a number of these have reached the development stage. Production is being expanded from the known fields, such as Wabana in Newfoundland and Michipicoten in Ontario."

Jan 1, 1955

By T. W. Wlodek

"AbstractThe results of research into the fatigue properties of SAE 1080 carbon steel and nickel-chromium-molylbdenum steel for mining drill rods are analysed and described in detail.The effect of water corrosion on the fatigue strength of drill rods of these two steels in the as-rolled condition has ,been investigated and the beneficial influence of shot-peening on their dry and water-corrosion fatigue strengths determined by employing the method developed previously (1).Eight S-N curves for as-rolled and shot-peened mining drill rods under both dry and water corrosion conditions have been derived and their shape and relative position are discussed. The main features relating to field performance of the drill rods are analysed.Purpose of Research and Outline of ProgrammeDRILLING holes in rock and ore by means of drill rods attached to a pneumatic drill is a basic procedure required in mining operations. Detonation of explosives placed in these holes is at present the only practical method of breaking down the rock and ore.A drilling rod is supported by its bit end in the drilled rock. Its shank end, fixed in the drilling machine, transmits impact energy to the cutting edges of the bit. On the field performance of the drill rod depend a number of basic mining operations such as sinking, drifting, and stoping. The drill rod is there-fore regarded as one of the most important tools used in the mining industry."

Jan 1, 1952

By R W. Drybrough

The program to increase production at Sherritt Gordon's Lynn Lake property, which began in 1956, included increasing the rope speed and the horsepower of the ore hoist at the "A" shaft. Because of the limited power sup-ply from the two 7,000-hp. hydroelectric plants, and the ? 3,600 hp. predicted for the combined hoisting requirements of the three production shafts, it was considered desirable to lessen the impact of this type of load on the relatively small power system by equipping all future hoisting arrangements with Ward Leonard direct-current drives. The manually operated 8-by 4-ft. hoist at the "A" shaft had a rope speed of 1000 f.p.m., and was driven by a 385-hp., 380-r.p.m. wound rotor motor with liquid rheostat control. This A.C. drive was replaced by a semi-automatic Ward Leonard direct-current drive with a 515-hp., 566-r.p.m., shunt wound motor, providing a rope speed of 1,500 f.p.m. During several months preceding the con-version, all possible preparations were carried out to keep the changeover period to a minimum, and this resulted in a total shutdown time of twelve days. The capability of the "A" Shaft hoist was increased from 109 tons per hour to 134 tons per hour, and both mechanical and electrical maintenance were reduced considerably. The total cost of the conversion amounted to $130,000. The hoistmen who had been required for the manual A.C. drive were transferred to the new Farley shaft, and the reduction in operating labour costs of the "A" Shaft hoist

Jan 1, 1965

By H. L. Martin

A joint federal-provincial approach in gathering basic information from industry on mine production, concentrator operations and ore reserves, initiated during 1978, is a major step toward the goal of achieving better government-industry communication through a common data base. Information from questionnaires sent out by provincial governments is shared with the federal government; correct interpretation is ensured by mine visits conducted jointly by provincial and federal representatives. Initial focus is on nonferrous metal mines. The federal Department of Energy, Mines and Resources (EMR) is responsible for a national analysis that is aimed at the early detection of worrisome developments-and their reasons-in the flow from resources to reserves and from reserves to supply of these metals. The heart of the national analysis is the annual construction of a "monitoring curve", showing each metal's aggregated mine production as it would decrease over time if no new reserves and production capacity were to be added from the year of analysis. For a given metal, a comparison of monitoring curves from year to year can reveal early signs of supply stagnation. In anyone year, a monitoring curve in conjunction with foreseen needs for Canadian mine output will show the production gap that would have to be filled from reserves and production capacity yet to be developed. The production gaps for copper, nickel, zinc and lead, the four leading base metals mined in Canada, are shown for the 20-year period ahead, in the context of production achieved during the past 20 years. It is shown that reserve levels commensurate with likely future production levels would require that average annual reserve additions during 1978-98 exceed the average annual additions during the preceding 20 years. Reserve levels of all four metals have declined in recent years. A review of significant discoveries in the last five years suggests that this fall in reserves is not the result of a lack of exploration successes, but of stagnation in development for various economic reasons.

Jan 1, 1979

By G. G. W. Thom, A. A. F. Schuldt

At The Steel Company of Canada, Limited, iron oxide dust from the basic oxygen open hearths is being collected by means of electrostatic precipitators. The utilization of this dust, which has been hampered by the presence of zinc and lead oxides and sulphur compounds, is made possible by direct reduction in a rotary kiln. The description of the dust collection system and the results of kiln tests are presented.

Jan 1, 1966

By M. Vallée

Several reviews of mineral project performance in the past 35 years indicate a pattern of occasional, but recurrent, mining project failures due to shortcomings in geological information and estimation, mineral processing and metallurgical testing, feasibility study objectives and requirements, and project start-up methods. A commitment to quality assurance and continuous improvement methods and to obtaining “ENOUGH DATA, OF APPROPRIATE QUALITY” is essential. Recent international and Canadian proposals for mineral resource and ore reserve definitions have taken a nonprescriptive stance that will undermine the formulation of requirements, guidelines and industry standards for efficient deposit delineation and estimation, and for the determination of project feasibility. To help reduce problems, every feasibility study supporting a mine development and production decision should be based on objectives and methods adequate to reach completion targets similar to the bankers’, as a good business target for a profitable project. In a resource/reserve system, the use of reserve should be restricted to a project that meets required technical, economic and legal feasibility requirements for successful project implementation, and the definitions of these categories should provide explicit limits. Current shortcomings will limit the ability of the Qualified Person to provide “adequate professional practice,” fulfill his/her professional responsibilities to his employer or client and provide adequate information to the investing public. We must take advantage of present opportunities for Setting New Standards for the new Millennium.

Jan 1, 2000

By Tim Martin, Dave Tahija

"In April, 2014, Hecla's Greens Creek mill, near Juneau, Alaska, switched from sulphuric acid to the use of dissolved carbon dioxide for lead flotation circuit pH control. The Greens Creek mine uses paste backfill, in which mill tailings are mixed with cement and used to fill mined areas. Some backfill inevitably becomes part of mill feed during subsequent mining cycles, resulting in high feed pH levels and increased dissolved calcium in the lead flotation circuit. Sulphuric acid is traditionally used to lower pH in such cases but it produces undesirable side effects, including poorer lead-zinc separation and unstable froth. The amount of sulphuric acid used at Greens Creek was limited due to these effects, resulting in higher than target pHs when feed backfill content was high. Dissolved carbon dioxide can be added without these limitations so pH levels have been under much better control since the switch. Additionally, lead-zinc separation and froth characteristics have significantly improved.IntroductionThe Greens Creek Mine, owned by Hecla Greens Creek Mining is an underground mine located on Admiralty Island near Juneau, Alaska, producing silver, gold, lead and zinc in the form of lead and zinc flotation concentrates and a gravity gold concentrate (McDonald, Morgen & Hancock, 2012). The lead and zinc concentrates are produced in conventional flotation circuits preceded by a graphite removal flotation step.The underground mine utilizes cemented paste backfill, of which a certain amount is inevitably re-mined in later mining cycles and returned to the mill, mixed with fresh ore. The Portland cement used in the paste backfill is highly basic so that, from the point of view of the mill, the net effect is to introduce a good deal of lime to run-of-mine mill feed, producing a very high natural pH. This high pH needs to be lowered to obtain good metallurgical results."

Jan 1, 2016

By C. R. Whittemore

PROGRESSIVE industrial organizations have recognized the importance of maintaining an adequate reference library of volumes covering all phases of their particular branch of industry, but it has been the experience of the writer that few engineers know how to use to the best advantage this store of extremely -valuable information which has been accumulated for their service. Nor does the average engineer appreciate the fact that it is only through the current technical literature that he can keep abreast of the rapidly developing fields of engineering. The present-day ramifications of the engineering field are of such wide scope that the human mind is not capable of storing away more than a small fraction of the information available on any particular topie; yet, from time ? to time, such information would prove invaluable. An engineer can know intimately only a small part of his own branch of engineering; but he cannot afford to neglect to take the fullest possible advantage of all that is already known in his own particular field. Technical information may be obtained by one or more of the following methods: (1) by enquiring of the individual who knows; (2) by performing the experimental investigations necessary to ascertain the facts; (3) by consulting the technical literature, where a record may be found of the work of others. This last method is the one we wish to examine. Our main consideration is the question of how to use the library, but first it is necessary to give some attention to the kind of enquiries one takes to the library, and to the nature of the sources of information available.

Jan 1, 1938