Search Documents

By J. E. Hawley

"IntroductionA STUDY of the trace elements in the ash •of coals from nine seams in the Sydney coalfield, Nova Scotia, was undertaken at the suggestion of Dr. W. A. Bell, Geological Survey of Canada, as a part of a larger study of these and other Nova Scotia coals being made by the Geological Survey and the Nova Scotia Department of Mines under the direction of Dr. P. A. Hacquebard.The main purpose of this investigation has been to •determine if a knowledge of the trace element distribution might be of assistance in the recognition of individual seams, the distinction of which is not always easy or positive in folded and faulted strata by ordinary stratigraphic and structural means.The study has been so conducted as to afford information on the variation of trace elements in individual petrographic intervals or divisions in each of the seams examined, intervals determined by Dr. Hacquebard on the basis of their banded ingredients, vitrain, clarain, durain, fusain, etc, as observed under the microscope in polished sections. The results, as well, indicate the trace element composition of the coals of the area as a whole, and quantitative data for fifteen elements are given, along with concentrations of thirteen other elements, stated in terms of intensity ratios. Data on distribution of germanium, though considered here along with other elements, are dealt with elsewhere*."

Jan 1, 1955

By G. J. Birnie

Introduction The preparation of the following paper has been undertaken in the belief that a description of the development methods and equipment used at Lake Shore, at the present time, will prove of general ? interest. Working depths of nearly a mile and a half in shaft sinking and of more than one mile for stoping operations have imposed problems not encountered at shallower horizons. Among the problems contributing to the difficulty of mining at extreme depths might be mentioned: Rock pressures Ventilation Hoisting Shorter work period at the face Geological considerations In the main, the effects of these factors add to the difficulty of mining at depth, but it is not entirely true to say that each must necessarily become more pronounced as mining operations proceed to greater depths. Corrective measures may, in some cases, retard the effect and in others may even relieve some of the difficulty. It is proposed here to discuss these features in the light of the experience at Lake Shore, and to present, in some detail, the current practice in shaft sinking and in driving ore and waste passes, raises, drifts and cross-cuts.

Jan 1, 1950

By James H. Cobbs

Blind boring of shafts is becoming an increasingly important part of shaft sinking. Blind-bored shafts have reached diameters of 25 It in Europe and 16-1/2 ft in the United States. Much of the technology developed for blind boring has evolved from the technology of drilling wells for oil and gas production. Blind boring offers economic advantage in a number of situations where conventional shaft sinking either is extremely difficult or very expensive by virtue of large-capacity aquifers which must be penetrated, unstable ground or where very rapid sinking is required. In sedimentary rocks, blind boring is cost competitive with conventional sinking, in diameters of about 12 ft or less. Blind boring is not competitive with raise boring where conditions are favourable for raise boring. Blind boring does, however, offer greater flexibility than raise boring and can be performed in situations where raise boring is inefficient or impossible. Combination machinery has been developed to perform both blind boring and raise boring, so that the machine can be used effectively in situations where only the near-surface portions of the shaft are unfavourable for raise boring. Development work is being supported by the United States Bureau of Mines for blind boring equipment capable of boring shafts up to 30 feet in diameter.

Jan 1, 1979

By R. C. Gilmore

Underground longwall coal mining sections may develop explosive mixtures of methane-air in the mined-out gobs. If the panel are operated as bleederless or sealed gobs, progressive sealing along the gate roads as the longwall face retreats limits the flow of fresh air into the gob and thus deprives potentially explosive atmospheres of oxygen. In a project sponsored by the National Institute for Occupational Safety and Health (NIOSH), researchers at the Colorado School of Mines have used computational fluid dynamics (CFD) modelling to simulate the flow of gases in longwall gobs. Modelling indicates that targeted injection of nitrogen through the seals along the gate roads inbye the face can be used to control the size and location of methane and air clouds within the gob and to minimize or eliminate the explosion hazard resulting from the formation of flammable methane-air mixtures in longwall gobs.

Aug 1, 2013

By H. Hitchen

THE object of this paper is to present the various facts that l1ave been revealed during lengthy investigations into the performance of all types of ropes on different hoisting installations. It then goes on to suggest means by which most of these findings could be usefully employed to obtain more economical rope lives with increased safety. SHAFT HOISTING ROPES Four basic designs of ropes are now employed for hoisting duties: (1) Six-strand, round strand ropes with fibre cores. (2) Six-strand, triangular strand ropes with fibre cores. (3) Non-rotating, multi-strand ropes. 0) Locked coil ropes. Round Strand Ropes (Figure 1) Very solid and reliable ropes can be obtained with this simple geo-metric design of strand. 1'1?iangula1? Strand Ropes (Figure 2) Owing to the fact that the wires in the strands are bent over a triangle, they do not seat quite so solidly as when they are bent over a circular core wire, as is the case with

Jan 1, 1963

By E. Herrera Alarcón, L. Mariscal Samaniego

The Teniente Converter (wet charge type) was commissioned in august 1995 and was designed to smelt 744 tpd (metric tons per day) of dry copper concentrates. Its products are white metal (73% Cu) that is sent to the Peirce Smith converters, slag that is cleaned in Reverberatory Furnaces and the process gases that are sent to the Sulfuric Acid Plant. Since its start up, the Teniente Converter smelting capacity was increased 1.6 times, from 800 tpd to 1,280 tpd using 33% oxygen-enriched air, and reaching an operative availability of 97%. By the other hand its campaigns have reached a record duration of 530 days without hot patching tuyeres and a partial refractory lining repair in the last four campaigns. This paper describes the most relevant improvements, as well as the strategies that had been used to reach these achievements.

Jan 1, 2007

By G. R. Cope, J. S. Getsinger, K. D. Lund, T. Neale

"Mineral exploration in the Sicker Group, a belt of Paleozoic volcano-sedimentary rocks on Vancouver Island, has traditionally centred on auriferous polymetallic volcanogenic massive sulphide deposits such as those currently mined by Westmin Resources Ltd. near Buttle Lake. Recently, however, the focus of exploration in the Sicker Group has shifted toward targets of structurally controlled gold concentrations, with notable success. Major north and northwesterly-trending structural features such as the Cowichan-Horne Lake break (one of several regional high-angle thrust fault s active throughout a long period of geological time) and related fault systems have contributed to localization of gold mineralization.Using the extensive information database compiled by MPH Consulting Limited during numerous exploration projects in the Sicker Group, two cross sections through areas with significant gold occurrences southeast of Port Alberni are presented. The cross sections combine geological, geochemical and geophysical data in an attempt to emphasize the relationship between structural trends and gold mineralization. Examples from specific properties, including gold discoveries along the Mineral Creek fault zone, are used to illustrate this relationship."

Jan 1, 1990

By W. E. Uren

The Dominion Coal Board was created by Statute passed on July 17th, 1947, and was brought into effect by proclamation on October 21st, 1947. It is, consequently, a comparatively young body, having been in existence for only eighteen months. Before dealing with the constitution and duties of the Board, it may be well to answer the unspoken question of why it has been considered necessary to single out coal as one specific mineral requiring the continuous attention of a specially created permanent Board. In Canada, coal has been the neglected sister of the more spectacular minerals and it comes as a surprise co many to note that in 1948 the value of the coal produced in Canada was higher than that of any other mineral with the one exception of gold. Coal touches upon our daily lives in many different places of which the public are not generally conscious. As household fuel, it is a necessity of life in this northern climate; as a source of steam, it provides the heat for most of our industries; it is the food of the 'iron horse' chat shuttles our persons and our goods across the land; it is the source of power in many parts of the country; it is the chemical reducing agent chat, in our furnaces, transmutes the metallic oxides to the virgin metal. Coal is, in fact, the indispensable mineral chat forms the corner-stone of our present structure of industrial civilization. Is it, then, such an odd thing that the provision of an adequate supply of coal should be a matter of national interest or that measures should have been taken by government co provide for a constant watch, by a permanent Board, on the supply of co al? ? The Board is the result of the recommendations of the Royal Commission on coal which made a long and detailed study of the Canadian coal problem. It is composed of a permanent Chairman and six part-time members, most of whom have had intimate contact with various phases of the industry.

Jan 1, 1949

By S. Averill, B. Schreiner, V. Sopuck

The La Ronge. Kisseynew, Glennie Lake and Flin Flon domains. the main focu for gold exploration in the southeast part of the Saskatchewan Shield, were subject to continental glacial ice advances from the northeast during the Quaternary. Based on forty-four auger hole along with surficial mapping, the general Quaternary stratigraphy in this area is observed to be composed of a lower till unit , an overlying stratified unit of glaciofluvial sand and gravel and/or a glaciolacustrine silt-clay unit. an upper till. and an upper tratified unit. The lower till is commonly found throughout the geological domains except where it has been eroded in glaciofluvial or fluvial channels. Glacial Lake Agassiz fo rmerly covered most of these prospective domains. The lacustrine deposits associated with the lake impede surficial geochemical surveys including soil. lake sediment. and biogeochemical surveys. The approximate extent of clay cover can be predicted from beach elevations. For instance. in the Waddy Lake area. clay i not known to occur above about 1,400 feet (425 m) elevation. Exploration techniques are hampered by clay in at least one third of the volcanic belt. Thi s influence is indicated by the fact that nearly all gold prospect found to date are located above 1,400 feet (425 m) while the area of clay cover is vi rtually unexplored. The upper till i related to a minor ice readvance. This till is the medium often sampled during soil surveys in the area . lts value as a geochemical ampling medium is dependent on the extent of erosional contact with bedrock highs on the lower till. Those areas which are relatively free of lacustrine and fluvial deposits are those where surface geochemical methods work best. In the Waddy Lake volcanic belt approximately 25-50% of the area may be suitable for surficial surveys. The area of the Star Lake prospect occurs above the 1,500 foot (460 m) elevation and was not covered by Lake Agas iz. The effectivene of till sampling as a surface sampling medium was tested in those areas above the clay level. Till orientat ion surveys were carried out at the Star Lake property and the Tower Lake prospect (Waddy Lake area) within the La Ronge Domain . Gold grain counts and analy es of heavy mineral concent rate from 7 kg surface ti ll samples were used to delineate dispersion trains down-ice from mineralization. In addition, the clay fraction and a 30 g (-80 mesh) subsample from the same till sample, were analyzed for gold . In the Star Lake area, ice direction is subparallel to the strike of several narrow northeast trending auriferous structures. arrow dispersion trains down-ice from known

Jan 1, 1986

By M. R. Khalesi, S. Bellec, C. Bazin, D. Hodouin

This paper proposes a classification model to predict the split coefficient of gold ore particles as a function of the particle size and gold content. The model is calibrated and validated using data obtained from the sampling of an industrial grinding circuit. Model calibration is based on a complete simulation of the circuit and involves parameters related to the gold grain distribution in the ore as well as a grinding and liberation model. Since cyanide is added into the studied grinding circuit, assumptions related to gold dissolution in the mills are made to allow simulation results which reflect industrial behaviour patterns.

Jan 1, 2011

By Robert Drummond

Away back in the eighties of the last century, when Sir Charles, then Doctor, Tupper, was not only a prominent but a dominant figure in the political life of Nova Scotia, his opponents brought the railing accusation against him that he was the foremost of egotists because of his frequent use of the personal pronoun. I heard Tupper speak and had no sympathy with the railers, because I could not well see how the pronoun could be dispensed with without laying himself open to a charge of affectation. I shall make reference in what follows to incidents in which I have taken part, and shall be at no pains to dispense with the pronoun, even though thereby I lay my-self open to the charge of being a pupil of the deceased states-man. EVENTS LEADING UP TO THE ORGANIZATION OF THE PROVINCIAL WORKMEN'S ASSOCIATION The Springhill Mining Company began development work at Springhill in the early seventies of last century. So vigorously was the work prosecuted that in 18 7 4 two slopes, the east and the west, were in active operation, with a considerable. output, the east slope on occasional days producing 800 tons. The President of the Company, the late Senator McFarlane, was a Nova Scotian, the other directors were mainly merchants from St. John, N.B. From the first the enterprise was an .astonishing success, due in the greatest part to its geographical position, and in large part to the untiring vigilance of the directors, a majority of whom visited the collieries at short intervals, thereby keeping the manager, much of the time, on tenter hooks.

Jan 1, 1924

By J. Gordon Parr, D. A. Whitaker, G. A. Yorko

High purity alloys of zinc with 25 per cent to 50 per cent aluminum, have been prepared. Mechanical properties of the as-cast and heat-treated alloys have been related to constitution, determined by x-ray diffraction and microscopic methods. Investigations include the effects of aging and of small nickel additions on the properties of the alloys.

Jan 1, 1960

By William C. Martin

"Consolidated Sudbury Basin Mines Limited owns two mines, 4 miles apart, near the southwest end of Sudbury Basin. The Errington mine lies close to the north boundary of Creighton Township and about 18 miles by car from Sudbury. The Vermilion Lake mine is in Fairbank Township, on the south side of Vermilion Lake.The first discovery of base-metal mineralization within Sudbury basin was made by James Stobie in 1897 at Stobie Falls on the Vermilion River, half a mile west of the Errington mine. A few years later Alphonse Oilier made a discovery of massive pyrite with base-metal sulphides near the west end of the present Errington workings.No work of consequence was done on these discoveries until 1924, when Joseph Errington acquired options on a large acreage of ground which was later taken over by the Treadwell Yukon Company Limited. After considerable diamond drilling this company sank No. 1 shaft in 1926. In the next three years, a large amount of underground development was done, a pilot mill was constructed and operated for two years. All operations ceased in 1931 with the fall in metal prices. While in operation the pilot mill treated 186,172 tons of ore the average grade of which was 1·07 per cent copper; 1 10 per cent lead; 4·60 per cent zinc; 0·03 ounces gold; and 1 70 ounces silver.Up to the time of closing in 193 l there had been completed at the mine 26, 790 feet of lateral work and 75,500 feet of surface and underground diamond drilling. The company records, however, showed no figures on ore reserves, except broken ore in stopes amounting to about 60,000 tons. A study of the plans, prior to reopening the mine in 1952, showed 1,450 lineal feet of ore (at 1952 prices) opened up by drifting on the 300-foot and 500- foot levels. It is clear that no comprehensive picture of the structure was had at this time. The orebodies were considered to be very irregular pods scattered through masses of quartzite-carbonate in a sheared zone about 800 feet wide. In some way the ore was believed to be related to the tuff-slate contact zone. With this picture it was impossible to make a reasonable ore estimate or even gauge the tonnage potentialities with any feeling of reliability."

Jan 1, 1949

By Norman A. Grant

"Location and Transportation FacilitiesTHE BEAVERLODGE area of North Saskatchewan is on the north side of lake Athabasca, 500 air miles northeast of Edmonton.The main Eldorado operation and townsite are on the north •side of Beaverlodge lake, which is immediately north of lake Athabasca and is separated from it by only a mile long portage at Lodge bay. The once famous town of Goldfields. Saskatchewan, and the Box property of the Consolidated Mining and Smelting Company of Canada, Limited, are located on lake Athabasca nine mines from Beaverlodge townsite.Previously, all Eldorado freight was delivered by barge at the Lodge Bay portage, hauled across the portage, and across Beaverlodge lake by small Northern Transportation Company barges, which involved many handlings.In 1952 the port of 'Bushell' was established at Black bay. This is a particularly snug harbour, well protected from the main body of the lake and with good foundations for docking facilities. A Butler building, 300 ft. by 60 ft., and tank farms provide storage at the port. A •road from Bushell to the main Beaverlodge operation, a distance of twelve miles through rugged terrain, was built by the Saskatchewan Government. The cost was shared by the Saskatchewan Government, the Federal Government, and Eldorado and other mining companies.Along this road are located the properties of several enterprising mining companies and near the midpoint lies the ambitious budding town of Uranium. This road has made portaging unnecessary and palletized freight loaded at Waterways, Alta., is now loaded directly on trucks at Bushell and delivered to the point of consumption."

Jan 1, 1953

By Jr. Watts, B. K. Cantrell, K. L. Bickel, J. F. McDonald

"A field trial was conducted at an underground gold mine to evaluate diesel fuel derived from soybean oil (soy-methyl-esters or “biodiesel”) as an alternative to commercial, low-sulphur, number 2 diesel fuel (D2). A 2.7 m3, 18-ton load-haul-dump (LHD) unit, powered by a naturally aspirated, indirect injection (pre-chamber), 100 kW diesel engine was used as the test vehicle. The LHD was equipped with a diesel oxidation catalyst. The LHD operated satisfactorily on the biodiesel fuel. Operators observed a slight decrease in power and an absence of black smoke.Diesel particulate matter (DPM) concentrations were monitored for a six-week period while the LHD was operated with either the biodiesel fuel or the D2 fuel. DPM concentrations were measured in the mining section’s clean air intake, exhaust and on the LHD. Reduction in DPM emissions was determined from the measured difference in DPM concentrations between the clean air intake and the exhaust. The biodiesel fuel reduced energyspecific DPM emissions approximately 75%, from 3.6 ± 1.8 g/kW-hr to 0.86 ± 0.27 g/kWhr. Time-weighted average DPM exposure, measured near the LHD operator, was reduced from 0.67 ± 0.13 mg/sm3 to 0.28 ± 0.12 mg/sm3, or approximately 58%, when the biodiesel fuel was used. IntroductionDiesel exhaust consists of noxious gases and diesel particulate matter (DPM). Recent attention has focussed on the potential carcinogenicity of DPM and the potential health impact on miners. The National Institute for Occupational Safety and Health (NIOSH) recommended that whole diesel exhaust be regarded as a “potential occupational carcinogen”, and that reductions in workplace exposure would reduce cancer risks (NIOSH, 1988). The International Agency for Research on Cancer (IARC) declared that “diesel engine exhaust is probably carcinogenic to humans” (IARC, 1989)."

Jan 1, 1997

By L. H. Thorleifson

Demand for both gem and industrial diamonds is very strong. Synthetic production supplies industrial uses, but synthetic gems remain inferior and expensive, so the large gem market is supplied by mining. Several major mines have been depleted, and the market is receptive to new sources of high quality gems. Canada's Precambrian terrane, extending across the Canadian Shield and under the Phanerozoic cover of the Plains and Hudson Bay, has excellent potential for diamonds, but exploration conditions are difficult due to recent glaciation. Early world exploration relying on recognition of diamond in alluvial sediments was adequate to launch pre- 1900 production from India, Brazil, and Africa. Exploration success in Canada, as was the case in Russia and other more recently discovered sources, however, had to await large investments in effort supported by advanced science and technology. Canadian exploration in many ways is similar to that in other regions, relying on analysis of tectonics, indicator minerals, geophysical surveys, and multiple stages of drilling and sampling. Very different from other regions, however, is Canada's surficial environment, in which recent glaciation has caused fresh indicator minerals to be transported hundreds of km. Exploration accelerated in Canada after 1960, first in Ontario and the Arctic Islands, then in Saskatchewan in 1988, and most importantly after the Chuck Fipke - Stew Blusson discovery at Lac de Gras, Northwest Territories, in 1991 that led to the billion-dollar BHP - Dia Met Ekati Mine that opened in 1998. In 2003, production from Ekati will be supplemented by that from the similar and nearby Diavik Mine of Rio Tinto and Aber. These mines will bring Canadian output to over 10% of world supply, and will position Canada with Botswana and Russia as world leaders in production of high quality gem diamonds. There could be other mines as well, as sites across the Arctic and in the south from Alberta to Québec are being explored by an array of companies, including De Beers, other majors, and several juniors.

May 1, 2003

By Ling Wu

The development of pyrometallurgical technologies has been focused on new smelting reactors, but the proposal for new converting reactors has been substantially lower. Up to today about 80% of copper matte is treated by the traditional P-S converters which have the weakness of pollutant fugitive emissions. Therefore, the continuously converting processes for treating molten matte have been studied and developed. In July 2017 the "oxygen-rich side blowing smelting + multi-lances top converting & fire refining" continuous copper treating process was commissioned. This process was designed by ENFI and YanTai GuoRun Copper Smelter. In this process, oxygen rich side blow technology is adopted for smelting, which is a new type of side blowing smelting furnace to produce high-grade copper matte. The converting adopts the horizontal multi-lances top-blowing continuously converting process, which eliminates the transportation of molten melt and the SO2 fugitive emission. The intermediate products of this process, copper matte and blister copper is fed into the furnaces respectively through launders. This new process is more advanced, more reliable and more environmentally friendly. Until now, this process in the GuoRun copper smelter is operating smoothly. An increasing number of projects which use this process are under design and construction in China. INTRODUCTION At present, there are many advanced smelting technologies for copper concentrate, such as oxygen bottom blowing smelting, flash smelting, top lance smelting (including ISA and Ausmelt furnaces smelting), side blowing smelting, Mitsubishi smelting, etc. At the same time, there are many copper matte converting technologies such as oxygen bottom blowing continuous converting, flash converting, Ausmelt top lance converting, horizontal multi-lances top blowing converting, Mitsubishi converting, P-S converter converting, etc. The final blister copper fire refining technology mostly adopts rotary anode furnace. Therefore, in the process of processing and extracting the copper from concentrate to produce anodes, there are dozens of technology combinations. Among them, the non-continuous converting technologies for molten or cold matte are often adopted in the converting process. The traditional P-S converting technology had been utilized for over one hundred years, with a mature, reliable and simple operation, also has advantages in the secondary scrap smelting of a wide range of quality. However, due to its batch operation, frequent roll in and out, poor sealing, considerable air infiltration, needs for ladles for molten phases transportation and other characteristics, the technology has a serious pollution problem due to fugitive SO2. At the same time, in the cold matte converting technology, the molten matte needs to be cooled and then processed. The sensible heat of the molten matte cannot be recovered, and the preparation process is needed in the process. Therefore, both energy consumption and investment are relatively higher.

Jan 1, 2019

By K. S. Raja, F. Battick, B. Pesic

"CeO2 doped with lower valence cations, such as Y3+, Sm3+, Gd3+ etc. is considered as electrolyte material for low temperature SOFC. Doping introduces additional oxygen vacancies and improves ionic conductivity. This work describes the preparation of yttria-calcia doped-ceria precursor material, its sintering in DC and AC field methods, and characterization of sintered electrolytes with respect to the ionic conductivity. Doped precursor materials were prepared by a controlled co-precipitation process. Sintering of prepared, pelletized particulates was carried out using three different methods such as: 1) conventional; 2) spark plasma sintering; and 3) an alternating current field at 1125°C (AC assisted sintering). The mechanism involved in the conductivity improvement as a function of defect density, grain boundary area and phase stability will be discussed. INTRODUCTIONThe performance of SOFCs depends highly on the properties of materials. Subtle variations in the composition, microstructure, or density of SOFC components can considerably alter the power output capabilities of fuel cells. Early SOFCs utilized zirconia based electrolytes but efforts in lowering the operating temperatures of SOFCs have prompted investigations into several other oxygen ion conductors – often modified with dopants to either promote the formation of oxygen vacancies or to stabilize a vacancy rich high temperature phase – such as bismuth oxide, lanthanum gallate, and ceria.The transport of oxygen ions through the electrolyte first begins with diffusion into the material. While this is generally a surface kinetics phenomenon, it is safe to say that it is highly dependent on oxygen pressure and vacancy gradients. The role of the cathode in SOFCs is to reduce oxygen at the electrolyte surface creating an O2– ion gradient which induces permeation into the material. Once inside and under the influence of a potential field, O2– ions migrate by a vacancy hopping mechanism, Catlow, C.R.A. (1990), effectively exchanging positions throughout the matrix until they reach the anode and react, thus leaving the matrix."

Jan 1, 2012

By Steven Doyle

Presentation Outline ?Introduction to Brunswick Mine ?Mining Needs and Drilling Trends ?Maintenance Program ?Back to Basics ?Results ?Additional benefits Introduction Xstrata Zinc Brunswick Mine ?No. 12 deposit discovered in 1953, pilot mining 1957, u/g mining began in 1964 ?Zinc, copper, lead and bulk lead/zinc concentrates ?Since 2007, a fully owned division of Xstrata Zinc Canada ?Over 132Mt milled 3.4 % Pb, 8.8 % Zn and 102 g/t Ag ?Deposit dips approximately 70 degrees; strike length of 1200 m; currently mining from 250 m to 1125 m depth

Nov 1, 2011

By Graham E. Brown

Since the beginning of time, people later to be known as engineers and architects have strained to create methods whereby they could improve technology to assist them in their various fields of endeavour. Some of these improvements would be the change from linen paper, french chalk and ink pens to drafting film , mylar an d pencil for the production of drawings, the drafting machine in lieu of the tee and set squares, even tap e to attach drafting media to the board instead of thumb tacks and man y, man y more. All of these taken individually are insignificant but combined evolve to the current state-of-the-art in the computerized engineering environment. Ten years ago the major topic o f conversation was the hand-held calculator which for a cost of around $150 would give most trigonometric functions. Today the equivalent calculator can be purchased for around $25, is about one third the size, and if inflation were included over the last ten year s the item should cost around $550 in today' s dollars, it can be seen that tremendous advances not only in the technology but also the cost saving. The following paper is intended to outline some o f the significant aspects o f the latest technology in the computerized engineering office namely Interactive Graphics Systems.

Jan 1, 1985