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By Leonard P. Vitt

This report details the work done to provide the U.S. Bureau of Mines with a customized Wireless Ground Monitor Wireless Ground Monitor was modified as follows: 1. A voltage regulator was added to prevent false trips with line voltage variations. 2. A Ground Wire Trap was designed to eliminate problems with parallel paths and provide spark suppression. 3. A three phase filter was designed to reduce 60 Hz leakage current. 4. A portable tester was designed to permit complete test of installed systems. 5. The design was modified to insure trip with an open ground wire in the event of a failure of any one semi-conductor component.

Jan 1, 1976

By Jongmin Jeong, Jaehong Shin, Joo Hyun Park, Chul-Woo Nam, Kyung-Ho Park

Because sulfur and phosphorus are very harmful in steel products, there are increasing requirements for refining these elements from ferroalloys industries. Hence, in the present study, simultaneous desulfurization (de-S) and reducing dephosphorization (Rde-P) from silicomanganese (SiMn) alloy were investigated using metal-slag equilibration method under highly reducing condition at 1773 K. Experiments were carried out by equilibration between SiMn alloy and MnO-based slag in graphite crucible under p(O2) = 10−18 atm. Slag composition was designed by changing basicity (CaO/SiO2) and MnO content at fixed Al2O3 (=20%) and MgO (=5%) contents. De-S ratio increased with increasing basicity until C/S = 1.5 whereas Rde-P ratio was not significantly affected by slag basicity. This was because thermodynamic driving force of de-S reaction was greater than that of Rde-P reaction under present experimental conditions. The de-S and Rde-P ratios commonly increased with decreasing oxygen partial pressure.

Mar 1, 2017

By S. Norman Kesten

The Resource Conservation and Recovery Act, commonly known as RCRA, which amends the previous Solid Waste Disposal Act, was signed into law on October 21, 1976. Members of the mining industry began their contacts with EPA in this area two to three years before the Act finally was passed, and that seemed and probably was all to the good. We reviewed and commented upon their studies and in general tried to acquaint them with the peculiarities and the uniqueness of the wastes generated by our industry, of which they were abyssmally ignorant. I suppose we thought that through the bureaucracy we might have some influence upon the provisions of the solid waste legislation that was being bandied about on the hill. Certainly the industry, in general, did very little direct lobbying, as I recall, and there were several reasons for that. For one thing we conceived that the legislation was aimed at the chemical industy and believed that if their people looked after their interests, ours would be safeguarded automatically. Also, the Federal Land Policy and Management Act (FLPMA) was heating up at the same time and, in fact, was signed into law on the same day. In addition, a great deal of lobbying activity was required by amendments of the Clean Air Act and Federal Water Pollution Control Act that were being put together in Congress. These were conceived to be of far greater importance to our industry than a bill to control mostly chemical wastes and, in fact, new bills in both areas became law the following year. Finally, the solid waste bill, RCRA, was patched together by committee staffs over one weekend and was reported out by a conference committee rather hurriedly. Some little goodies about mining were almost after-thoughts in this process.

Jan 1, 1981

By Riyad N. Ahmad-Bita, Shadia J. Ikhmayies

"SnO2:F/CdS:In structures were prepared by the spray pyrolysis technique on glass substrates at a substrate temperature Ts = 450°C. NH4F and HF were both tried as the sources of fluorine in the precursor solution of SnO2:F. A comparison between the properties of structures obtained by using the two doping compounds was performed. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmittance measurements were used to characterize the films. The structures prepared by using HF as a fluorine source were found to have more ordered crystal growth, larger grain size and sharper absorption edge. From the inspection of the first derivative of the absorbance it is expected that more interdiffusion on the SnO2:F/CdS:In interface takes place in the structures made by using HF. These results confirm that these films are better as forecontacts for CdS/CdTe solar cells.IntroductionThin film CdS/CdTe solar cells built in the superstrate geometry rely on transparent conducting oxides (TCOs) to make the front contact The investigation of combined CdS-TCO films has recently been developed owing to the great interest of better understanding the effect of these bilayers on the absorbers [1]. Usually SnO2 is utilized as a front contact for these solar cells. Optimizing the properties of the SnO2/CdS structures is an important step on the way to get high performance CdS/CdTe solar cells.There are different methods to prepare SnOz thin films, such as reactive sputtering [2], evaporation [3], chemical vapour deposition [3, 4], dip coating [5] and spray pyrolysis [6-9]. At the same time CdS thin films can be prepared by different techniques such as chemical bath deposition [10], thermal evaporation [11], screen printing [12] and spray pyrolysis [7, 13]. However, the spray pyrolysis technique is a very low cost and simple technique that enables intentional doping and getting large area and uniform thin films [14]. For these reasons it is choused to prepare SnOz and CdS thin films in this work. To improve the properties of these compound semiconductors, SnOz was doped with fluorine and CdS was doped with indium where such doping is well known for these compounds."

Jan 1, 2012

By E. S. Moore

THE Kolar gold field has been for a long time the most important gold-producing area of India. It is situated in the State of Mysore, southern India, and not far from the City of Bangalore. The productive field is about 3 miles long and in it a gold-bearing quartz vein varying in width from 1 in. to over 10 ft. is worked. The vein carries high values to great depths and many of the mines have paid large dividends. GEOLOGICAL FORMATIONS IN THE MOLAR REGION The rocks of the Molar region are pre-Cambrian in age and bear a close resemblance to some of the pre-Cambrian formations of America. The oldest rocks seen are basic lavas, now mostly altered to hornblende-schists, with which is associated some banded iron-formation; these rocks are similar to the Keewatin schists and iron-formation in the Lake Superior region. The schist is cut by the gold-bearing quartz vein. In certain parts of the area there is also a conglomerate containing pebbles of granite, jasper,, and schist. The matrix resembles a horn-blende-schist and is intruded by small granite dikes, which in some cases have been pinched off by squeezing of the rock. This has led Dr. W. H. Smeeth, Chief Inspector of Mines of Mysore, to whom the writer is greatly indebted for information regarding this area and for his hospi-tality while visiting the field, to regard this conglomerate as a breccia due to crushing of granite dikes in the schist. Dr. J. W. Evans has regarded the conglomerate as probably a squeezed glacial boulder clay. From analogy with pre-Cambrian conglomerates in America, the writer regards it as a metamorphosed rock similar to our basal Huronian conglomerate. However, the main bearing which it has upon the problem under discussion is the apparent fact that it is younger than the schist

Jan 3, 1918

The primary purpose of the Institute is to advance those sciences embraced by it through interchange of knowledge This can best be done by the presentation and discussion of technical papers by its mem¬bers Short practical papers are especially welcome In any case the author should satisfy himself that his material is of a quality that will be a credit to him and to the Institute The preparation of a good paper frequently leads to a reorientation of the author's thoughts, which is extremely valuable, and pertinent dis¬cussion thereof contributes in no small way to the professional standing of the author Members are urged to submit papers presenting the results of their work Attention to the following suggestions will greatly further the prompt and efficient handling of manuscripts 1 Subjects: The subject must be within the field of the Institute Original work, the results of field, plant, laboratory or theoretical investigations, new views on old but important problems and occasion¬ally reviews of timely and important subjects of wide interest to our members may constitute the basis of a paper The mere fact that the work is original does not necessarily justify publication it must be of a substantial nature, of value to a reasonable number of our members and worthy of permanent record It is rarely desirable to subdivide the results of a single research for publication in a variety of journals Pre¬vious publication is a bar to acceptance 2 Construction : Papers should be clearly and concisely written in good English Care in this regard insures wider reading and the saving in space permits the Institute to publish more papers The terminology and units employed should be those current in the particular field An examination of Institute publications will afford useful guidance in such

Jan 1, 1937

By F. Grajales Munoz

The Cienega project, now under construction by Penoles group, is located in the mountains of the State of Durango, Mexico. The gold and silver deposits are found in the 4-km long system of veins, which will be extracted by underground methods. The planned 1000 tpd process plant will contain a countercurrent cyanide circuit for oxide ore and a flotation circuit for sulfide ore. Considerable resources have been devoted to development of infrastructure in the isolated location, as well as for the mitigation of environmental impacts. Startup is scheduled for the third quarter of 1994.

Jan 1, 1994

By W. M. Deaton

The Keyes Helium Plant of the Federal Bureau of Mines was constructed under an expedited schedule, to supply the urgent and growing demand for helium in atomic energy, missiles, aerology, space exploration, shielded-arc welding, and low-temperature research. Construction began in December 1958 and ended in August 1959. The plant, near Keyes, Okla., processes 2 percent helium-bearing natural gas from the Keyes gasfield. In 1960 the plant produced and shipped 263 million cubic feet of helium (equivalent to an annual rate of 290 million cubic feet). Production cost was $9.11 a thousand cubic feet of helium. A low-temperature process involving two steps is used; the first separates a crude-helium product from the natural gas at about -250° F. and 225 pounds per square inch gage (p.s.i.g.); and the second purifies the crude helium to a high-purity product (Grade-A helium, 99.995 percent helium) at about -320° F. and 2,750 p.s.i.g.

Jan 1, 1961

By M. Cuba

Geostatistical modelling aims at providing unbiased estimates of the grades of elements of economic interest in mining operations, and assessing the associated uncertainty in these resources and reserves. Conventional practice consists of using the data as error-free values and performing the typical steps of data analysis - domaining, semivariogram analysis, and estimation/simulation. However, in many mature deposits, information comes from different drilling campaigns that were sometimes completed decades ago, when little or no quality assurance and quality control (QA/AC) procedures were available. Although this legacy data may have significant sampling errors, it provides valuable information and should be combined with more recent data that has been subject to strict QA/QC procedures. In this paper we show that ignoring the errors associated with sample data considerably underestimates the uncertainty (and consequently the economic risk) associated with a mining project. We also provide a methodology to combine data with different sampling errors, thus preserving the relevant global and local statistics. The method consists of constructing consistent simulated sets of values at the sample locations, in order to reproduce the error of each drilling campaign and the spatial correlation of the grades. It is based on a Gibbs sampler, where at every sample location, the actual sample value (with error) is removed and a conditional distribution is calculated from simulated values at nearby sample locations. A value is drawn from that distribution and kept only if it satisfies some statistical requirements-specifically, the global relative error and local means and variances must be reproduced. All sample locations are visited and simulated sample values are generated iteratively, until the required statistics are satisfactorily attained over all sample locations. This generates one realization of possible sample values, respecting the fact that the actual samples are known to carry an error given by the global relative error. Multiple realizations of simulated sample values can be obtained by repeating the procedure. At the end of this procedure, at every sample location a set of simulated sample values is available that accounts for the imprecision of the information. Furthermore, within each realization, the simulated sample values are consistent with each other, reproducing the spatial continuity and local statistics. These simulated sets of sample values can then be used as input to conventional simulation on a full grid to assess the uncertainty in the final resources over large volumes. The methodology is presented and demonstrated using a synthetic data-set for clarity.

Jan 1, 2012

By A. G. Taylor

High value materials, such as gold, platinum and other precious metals are subject to loss through unauthorized removal from mines, smelters, refiners, and other places where such materials are processed. A study published in 20011 determined that between 1994 and 1998 an average of 603 kilograms of gold per year was stolen from South African miners and subsequently recovered. This does not include the gold that was stolen but not recovered. At 2011 prices, 603 kilograms of gold would be worth approximately $33 million. Mine security personnel believe that the unrecovered stolen gold far exceeds what is recovered2. Traditionally, metal detectors have been used to screen personnel leaving secure areas to discourage such unauthorized removal. However, with the current near-record prices of gold, platinum, and other precious metals, it has become worthwhile for people exiting a facility to walk out with quantities of product that are too small for ordinary metal detectors to register, resulting in substantial financial losses.

Jan 1, 2012

By N. Wahl, D. M. Blackketter, R. Thornton

This paper evaluated using a water-filled abandoned mine (Orphan Boy) as a heat source for a 240- kW closed-loop heat pump with the goal of heating a 2,000-m2 building. The mine has a 245-m vertical shaft connected to a large stope by three horizontal cross-cut shafts. There is 1,250 x 106 L of water at a consistent temperature of 24-26° C that is available mostly in the stope. The only heat exchanger placement option is in the vertical shaft. Therefore, the focus was to model heat exchanger placement in the vertical shaft to determine the extent to which the systems will induce thermal currents between the stope and vertical shaft. Modeling of thermal currents, temperature profiles and heat contribution from the ground was done using finite difference and computational fluid dynamics. An optimal configuration was determined showing sufficient water movement and heat transfer will occur with a low water temperature in the shaft above 20° C. This project supports a U.S. Department of Energy (DOE) grant that will implement the full-scale system.

Jan 1, 2013

By Leandro de Arruda Santos

O objetivo deste trabalho é contribuir no desenvolvimento de novas soluções para a terapia endodôntica através do uso da análise por elementos finitos para avaliar o comportamento mecânico de instrumentos endodônticos. Primeiramente comparou-se os resultados de testes de flexão e torção com simulações realizadas sob as mesmas condições para validação. Uma vez validada a metodologia, pôde-se avaliar o comportamento de uma lima de NiTi CM em comparação a outras duas de aço inoxidável e NiTi superelástico com mesma geometria. As geometrias de dois instrumentos endodônticos comercialmente disponíveis foram submetidas a microtomografia computadorizada para a construção de modelos 3D. A malha de elementos finitos em ABAQUS e as condições de contorno foram baseadas em ensaios experimentais de flexão e torção de limas. Os modelos constitutivos foram obtidos a partir de curvas tensão-deformação em fios de NiTi superelástco, NiTi CM e aço inoxidável. Os resultados mostraram uma boa concordância entre resultados experimentais e simulados. O instrumento de NiTi CM apresentou-se como o mais flexível em comparação aos instrumentos de NiTi superelástico e aço inoxidável.

Aug 16, 2017

By G. Kipouros, M. Dadvand, A. Dadvand

"A novel methodology was developed to obtain a 3D porous layer with a high aspect ratio of porosity on a titanium electrode. The porous structure allowed more active material such as hydrous ruthenium oxide to be accommodated during the fabrication of the supercapacitor, resulting in an exceptionally high capacitance per surface area. The electrode demonstrated a remarkably high capacitance of 4,800 mF/cm2. The porous layer was composed of functionalized nanoparticles of TiO2 organized in a perfect 3D hexagonal close-packed array that resulted in a highly porous 3D structure. The layer was used as a template to electrolessly deposit a thin layer of silver prior to the electrodeposition of active material. KEYWORDS Capacitance, Porous, Ruthenium, Silver, Supercapacitor, Titanium RÉSUMÉ Une méthodologie innovante a été mise au point afin d’obtenir une couche poreuse tridimensionnelle (3D) affichant un rapport d’aspect élevé en termes de porosité sur une électrode en titane. La structure poreuse permet d’utiliser une matière plus active telle que l’oxyde de ruthénium hydraté durant la fabrication du supercondensateur, ce qui se traduit par une capacité exceptionnellement élevée par surface active. L’électrode affichait une capacité remarquablement élevée de 4 800 mF/cm2. La couche poreuse était composée de nanoparticules fonctionnalisées de dioxyde de titane (TiO2) organisées dans un arrangement regroupé parfaitement hexagonal en 3D, qui a engendré une structure en 3D hautement poreuse. Cette couche a servi de modèle pour le dépôt autocatalytique d’une fine couche d’argent avant l’électrodéposition de la matière active. MOTS CLÉS argent, capacité, poreux, ruthénium, supercondensateur, titaneINTRODUCTION There is a growing demand for integrating compact energy storage elements into electronic circuits due to the miniaturization of electronic circuits, sensors, and actuators, and the increasing importance of portable and wear-able devices incorporating more advanced electronic technologies that operate in controlled or uncontrolled environments to gather, process, store, and communicate information (Deng, Ji, Chen, & Banks, 2011; Beidaghi & Wang, 2012; Chen, Ramachandran, Mani, & Saraswathi, 2014). The manufacturing of compact energy storage elements needs to be compatible with the electronic circuit microfabrication processes. Recently, interest in integrating miniaturized supercapacitors into electronic circuits has increased due to their high charge–discharge rate and long operating life; however, ultra-high power miniaturized supercapacitors suffer from low energy density, hence requiring significant enhancement in their energy density for various applications (Deng et al., 2011; Beidaghi & Wang, 2012; Chen et al., 2014)."

Jan 1, 2019

[Admissions: Aurel E. Smith, Chairman Edmond F. Egan Lawrence S. Fennell John S. Fuller Howard J. Ritts, Jr. Gene E. Roark Kenneth W. Robbins Ben M. Gottlieb Advertising: Bernard F. Klein, Chairman Henry N. Lyle R. E. Howard H. M. Krause, Jr. Mrs. Evelyn R. Robertson]

Jan 1, 1961

By S. Leong

This paper reports on research examining disclosures from mining companies regarding their water usage in the Macquarie and Lachlan catchment areas, both parts of the Murray-Darling Basin in New South Wales, Australia. The objective of the research was to assess whether this disclosure is sufficient to allow communities to determine whether mining companies are complying with mining conditions of consent and abiding by the requirements of their water licencing agreements. These requirements are then compared to the water reporting requirements of the Global Reporting Initiative (GRI) and the Water Accounting Framework for the Minerals Industry (WAFMI). Communities are concerned about whether the mining industry?s use of water will have impacts on their livelihoods and lifestyle and thus require information concerning the quantity of water that will be extracted, how much water will be left for other stakeholders and whether the mining will affect water quality. This is an archival study. It has involved examining relevant publically available information released by mining companies and government regulators and determining if this is sufficient to meet the needs of the local communities. Additionally, it has involved looking at information indirectly provided by mining companies, via the use of intermediaries. Further, information availability concerning basic water accounting and regulatory breeches and whether such information is available at the mine site level has been considered. It is found that while NSW legislation places very little reporting requirements on mining companies, the development consent conditions for new projects and extensions to existing projects are quite significant and should be sufficient to meet the needs of local catchment residents though such information is not always easily accessible for the layperson.

Aug 1, 2013

By Wm. Hamilton Merritt

With the exception of the Vancouver Island coal, all the western coal-fields owe their present development to the completion, in the autumn of 1886, of the Canadian Pacific railroad. While it could not be expected that a very great deal could be accomplished in three years, enough has been done to pretty thoroughly establish the coal-bearing areas and their correspondence with those which have been developed to the south of the boundary along the lines of the transatlantic railroads in the United States. This summer I visited some of the important developments in the coal areas of Washington Territory, largely with the object of being better able to appreciate the corresponding coal-bearing areas in British Columbia to the north. In Western Canada, coal-bearing rocks have been found in three zones: 1. In the plains to the east of the Rocky Mountains and in the eastern flanking ranges, the coal occurs in the Cretaceous formation (including the Laramie). 2. In the interior plateau of British Columbia, the coal is found in the Tertiary formation. 3. On the coast of British Columbia, Cretaceous and Tertiary rocks are found carrying coal, and on the Island of Vancouver the well known Nanaimo coal has been worked for years in the first named formation. In all of these zones, the coals vary from lignites up to higher grades, the factor determining quality being the amount of pressute to which they have been subjected. The intensity of this pressure is generally shown by the disturbance which the coals exhibit, and, in many cases, is almost directly in proportion to the distance of the deposits from mountain ranges. This seems to be also the opinion expressed by Mr. Bailey Willis in connection with his Census Report on the coals of Washington. It has been elsewhere stated

Jan 1, 1890

By John M. Marek

INTRODUCTION This paper is for the mining manager, generally meaning mine superintendent, chief engineer, and others who have control over the mine operation responsible for feeding the insatiable beast called the mill or processing plant. The author is not from mine management but from the field of technical mine engineering consulting. This fact illustrates the authors gross inadequacy to comment on this subject. On the other hand, the consulting profession allows visits to many mine operations, worldwide, supplying many different commodities. The common complaints and misunderstandings that have been heard worldwide will be shared within the following few paragraphs. In order to discuss optimization, one must first define it. There certainly will be many papers in the following sessions that claim to optimize something, or other, based on a technical definition of cost, efficiency, throughput or some other quantifiable basis. DEFINE OPTIMIZATION Actual optimization of an operation is not as easily achieved as most of us in the technical world would like. Borrowing terminology from the technical world, the boundary conditions and the optimization function are usually not well defined. The problems in many cases do not lend themselves to quantification. Typical management procedures are to establish goals or strategies that set the approach or general boundary conditions to the overall plant. Three simple cases are listed below as possible corporate strategies to optimization of a mine-process plant complex. 1) Maximized discounted cash flow 2) Minimized long term cost of product 3) Maximized resource utilization This list seems simple when presented in the above context, uncluttered by constraints such as market position, capital availability, or environmental limitations. Sometimes the best approach is a prioritized combination of the above items. Typically, the Board or CEO has established these strategic priorities. They may

Jan 1, 1991

By Barnabas Bryan

In the year 1875, the Pennsylvania Supreme Court, acting on incorrect information concerning the production of oil and gas, established what has become the law of the land for the governing of oil production. While the decision was ideal for the refining monopoly which was completed in that year, there is no evidence that the court was in any way influenced by that refining monopoly. The evidence indicates that the court accepted the view of the royalty owner and independent oil producer. Throughout the life of the refining monopoly it accepted this law, which was so evidently to its advantage in securing cheap raw material. The same policy continued until the development of the exhaustion theory and the entry of the various units of the former monopoly into the production of crude oil. It is curious that no one doubted the new theory of shortage sufficiently to feel the need of changing the law. When the theory entered the economic field sufficiently to raise crude oil prices beyond justification it shortly disproved itself, but by this time the question of split ownership in producing fields made a change from legal error to justice too complicated to be undertaken by the large companies. Not even the ardent advocate of unit operation dared to carry the question to the United States Supreme Court, which has never been asked to pass on the complete question. The impossible position of the producing industry, hemmed in on one side by court law compelling wasteful production and on the other by the national law against cooperation, lasted until the demoralization of 1927 led to cooperation within a state and under state guidance. Since that time control of production has grown with the bringing in of each new field and at this time has the active support of the Department of the Interior in such ways as are definitely legal. As in 1875, the royalty owner and independent producer are opposing by all possible means the rational conduct of the business of producing crude oil. Fluctuation in Investments The investor in oil securities has not been as badly fooled as has the oil man himself. Fig. 1 is designed to show the composite regard of all

Jan 1, 1930

By Leonard G. Austin

INTRODUCTION Run-of-mine (ROM) coal generally falls into two major groups: that from underground mining (continuous mining machines) and that from strip mining. Continuous miners produce a finer product and strip mining a coarser product that is crushed to produce the desired size. Further size reduction depends on the proposed use or uses for the coal. For example, for pulverized coal power plants as a rough general rule, the coal is ground or pulverized to 80% less than 200 mesh (0.075 mm) before it is blown into the boiler furnace as a coal-air suspension. For solvent-refined coal processes, the desired size is about <30 mesh (< 0.60 mm); in fluidized bed uses, the coal is typically < 8, in. (< 1.6 mm); for Lurgi pressure gasifiers, the desired size is 1 to 2% in. (25 to 63 mm). Coal preparation plants typically work with a coarse size fraction of 6X 1/14 in. (150X32 mm). The past decades has shown a steady increase in the tonnage of coal cleaned, 1 but it seems probable that the next decades will produce much wider applica- tion of deep coal cleaning before use and that the stages of crushing and pulverization from ROM coal to end use will be integrated with coal cleaning processes. Since different cleaning processes work better with different ranges of coal size and the degree of cleaning possible is intimately connected with the size of coal, a systems design engineer will need as much information as possible concerning the size distributions produced by different types of machines and how these can be modified by different ways of operating the machines. In general, the following questions will be of concern: 1.What type of crusher or grinder is best, or most satisfactory, for reducing a given feed size and type of coal to a desired product size? Frequently, the desired product is smaller than some nominal size, but with as few fines as possible, or the fraction in some size range has to be as high as possible. 2. How big does the machine have to be for a given throughput rate? 3. How much electrical energy (or its equivalent) is required per ton of product? 4. How does the size distribution vary with change in throughput rate, and is a control scheme necessary or desirable? 5. Can the size distribution be readily varied if desired? 6. What is the optimum way to operate a machine in a given system? This section will emphasize certain general principles which guide us in answering these questions. PARTICLE SIZING Since particle size and size distribution are the raw information with which we work, it is worthwhile to review the terminology used. In this regard, see

Jan 1, 1991

By Thomas Robins

About six years ago the writer had occasion to visit a large magnetic iron-ore concentrating-plant, and then saw for the first time rubber belts employed for conveying-purposes. These belts were from 20 inches to 30 inches in width, and some of them were as long as 500 feet between centers. When I spoke of the enormous amount of material they handled with a small expenditure of power, the superintendent assented, but at the same time complained that although he bought the best quality of belts, the abrasion of the ore wore them out very rapidly, causing continually very large bills for repairs and renewals. On close examination several interesting points were discovered :

Jan 1, 1897