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By H. I. NORTON, H. O. Hofman

ZINC smelters in the central western. States have established a very high standard of purity for blende-concentrates, viz., zinc 60, iron less than 3, and lead less than 1 per cent. The very low percentage of iron is made possible by the blende containing less than 0.5 percent of isomorphous iron sulphide and by the sparing occurrence of pyritic material in the large blende-deposits of southwestern Missouri and southeastern Kansas. The blende in these districts occurs in sub-Carboniferous limestone, and is associated with chert, residual clay, calcite, pyrite or rnarcasite and bitumen. The different minerals are coarse and therefore readily separated by mechanical washing from the blende, with the exception of pyrite and marcasite, as blende has a specific gravity of from 3.9 to 4.1, marcasite, from 4.85 to 4.90, and pyrite, from 4.95 to 5.10. The common procedure of dressing the ores is to crush in a breaker, size in a trommel with 0.5-in. holes, pass the over-size through roughing-rolls and then jig the ore, now reduced to 0.5 in. maximum size, in roughing multiple-sieve jigs. The products of these are waste-tailings, sine-discharge coarse concentrates, side-discharge coarse middlings and bottom-discharge fine middlings. The coarse concentrates are sent to the market. The coarse middlings are crushed in middlings-rolls and brought back into the system by feeding into the main trommel. The fine middlings are cleaned upon finishing-jigs. Any pyrite or marcasite present follows the blende and increases the percent-

Mar 1, 1905

By Zay Jeffries

OF the new production of non-ferrous metals in 1930 gold will rank first in value. We usually think of copper as the most important non-ferrous metal. The copper industry as a whole, that is, adding copper production to copper fabrication, is the largest non-ferrous metal industry. Prior to the world war; however, gold led in value of new metal produced. During the war copper passed gold in value, but gold regained its position during the 1921 depression. For the past several years copper has again passed gold, but in 1930 gold promises again to regain the lead. The gold producer has at times been called a social parasite, largely because we ' cannot eat or drink gold, or because we cannot use it for clothes or for the construction of buildings. Let us briefly examine this accusation.

Jan 1, 1930

By James E. York

THE honor so fairly earned and so incompletely and tardily paid to Henry Cort, the inventor of the puddling-furnace and the, rolling-mill, has been fully set forth by Mr. Charles H. Morgan,1 and needs no further emphasis here. In view of the importance of the rolling-mill in the treatment of iron and steel, the paucity of information concerning it is surprising. With the exception of a hook, written about 35 years ago, by Peter Bitter von Tunner, an Honorary Member of this Institute, and of desultory articles on simple sections, which have appeared in technical journals, I know of no pub¬lication attempting to treat this subject, although volumes have been written on the scientific theory and technical manipulations involved in other branches of the iron- and steel-industry. This strange anomaly may be due to the fact that roll-turning cannot be called a scientific business. It does not ordinarily come within the range of an educated engineer; yet it cannot be performed by an ordinary mechanic. It demands some of the qualifications of an engineer, in designing, and those of a mechanic, in execution. The men who have followed this trade have controlled the training of their successors. In many cases the technical knowledge required bas been handed down from father to son, and there has been a motive of private interest to prevent its public dissemination. Moreover, the statement of the various principles involved in the process would require, besides manual experience, a degree of scientific knowledge which roll-turners do not usually possess; and, finally, any book on the subject, in order to possess real, practical value, would have to be so fully illustrated as to make it very costly to publish. Regarding my own experience, I may say that I served a six-

May 1, 1906

By Harrison Schmitt

DURING the past decade the writer has studied and mapped certain ore deposits and their structural associations in the states of Chihuahua, Durango, New Mexico and Arizona, and he believes that these deposits, with the exception of the manto-chimney, are representative of the principal types in the area of the states named. In this paper the deposits are described; then generalizations are drawn so far as seems appropriate. HANOVER, NEW MEXICO The Hanover; New Mexico, zinc deposits were briefly described by Lindgren and others,1 Paige2 and recently in more detail by Schmitt.3 These, the kind ordinarily called contact metamorphic, border the southern end of an oval area of granodiorite intrusive 3/4 mile wide and 2 1/2 miles long (Fig. 1). The granodiorite has intruded, folded, and metamorphosed sedimentary and igneous rocks, which range in age from pre-Cambrian to Upper Cretaceous. About 90 per cent of the ore has replaced coarse, recrystallized, pure, fossiliferous, lower Mississippian, nonmagnesian limestone (Hanover limestone) 110 ft. thick;4 about 75 per cent of it occurs in the upper 50 ft. of this horizon just below an 18-ft. lower Pennsylvanian shale bed, which lies on a locally inconspicuous unconformity representing upper Mississippian time. The orebodies show five shapes or attitudes, each dependent on a special structural situation: 1. Most of the ore occurs as podlike; thick lenslike or other "three-dimensional" shoots extending from top to bottom of the Hanover limestone and lying adjacent to the outer contact of a silicate zone largely of andradite, which follows the intrusive contact (Figs. 1 and 2).

Jan 1, 1933

By Lucius W. Mayer

The iron-mines of the Ilsede Hütte Co. are at a town called Peine, about 20 miles east of the city of Hanover, on the railroad to Brunswick (Braunschweig). Hanover, the capital of the province, is a military city, of approximately 250,000 inhabitants, and Brunswick, 33 miles to the westward, has half this number. The mines here described are located in a hamlet called Bülten. The Ilsede Hütte Co. operates two mines, 1.5 miles apart, in this district, Gruber Bülten Adenstadt and Gruber Lengede Bodenstadt. It also operates an iron-mine north of Hanover, known as Eiserhaven, and one in the Harz mountains, the Georg Friedrich, at Grauhof. At Bülten a coarse conglomerate, a, Figs. 1 and 2, contains nodules of limonite, cemented together by calcium phosphate. The ore contains Fe, 25 to 45; Mn, 3 to 4; P, 0.6 to 1.4; S, 0.02 to 0.09; and CaCO3, 40 per cent. Directly above the conglomerate is limestone, b, followed by a mixture of clay and sand, c. Below the conglomerate is a hard clay floor, d. The ore-body, from 10 to, 12 km. long, and from 3 to 4 km. wide, has a maximum thickness of 20 m. It clips approximately 10° S.E., and strikes N. 45° E. Diamond-drill prospecting shows that the thickness diminishes to 1 m. as the end of the deposit is approached to the northward. At this point the deposit is 250 m. below the surface. In Fig. 2, the arrow, A, indicates the general direction of the work along the face, a, which is carried forward in a straight line for its entire length. At B, a train is approaching, which has come from the bench-track, shown at G, by a circuitous route, and is dumping the overburden behind the face, in the space left by the excavated rock. Formerly the work at this mine was essentially open-cut, the deposit having a very strong outcrop. Figs. 1 and 2 show also

Sep 1, 1908

(Members, are urged -to send in for this column any notes of interest concerning themselves or their fellow-members,). Members and guests R: ho called at Institute headquarters during the period Dec: 10, 1916 to Jan. 10, 1917: F. L. Antisell, Perth Amboy, N. J. William Kelly, Vulcan, Mich. F. J Brulé, Toronto, Ont., Canada. W. H. Lanagan, San Francisco, Cal. Zar T. Crittenden, The. Pas, Mau, Canada. S. Lefevre, Forest Glen, N Y Thomas F. Donnelly, Tucson, Ariz. ' D. A. Lyle, St..David's, Pa. - John Davenport, Brighton, 14 lass. -Domingo Nugués, Buenos Aires, Argon-. E. E. Ellis, Birmingham, Ala. tine. N. H. Emmons, 3d, Copperhill, Tenn. - H. L. Scaife, Clinton, S. C. W.. E. Erdofy, New York, N. Y. Mortimer A. Sears, Washington, D. C. C. L. French, New York, N. Y. E. Spurny, New York, N. Y.' , M. H. Gannon, Butte,. Mont. R. K. Stockwell, Santiago, Chile. R. E. Hoffman, Hannibal, Mo. Benjamin F. Tibby, Salt Lake City, Utah. C. Vey Holman, Rockland, Me. Arthur P. Watt, St. Francois, Mo. Arthur P. Allen has left the employ of the Calumet &- Hecla Mine and is now with the Highland Min. Co., Ashcroft, B. C., Canada. H: C. Bellinger has been appointed. general manager of the Chuqui- - c mata mine-of the Chile Exploration Co. -

Jan 2, 1917

By James A. Clem

Approximately 2000 years ago, the Lord admonished the scribes (lawyers) and pharisees (religious leaders of that time) that they had paid the tithe but had omitted the weightier matters of law, judgment, mercy, and faith. (Matt. 23:23) I want to talk about "The Weightier Matters of Law." In a situation where big government is trying to have an effect on even small details of a work activity, otherwise simple situations become complex. Regulations are written to such detail that constant compliance with strict interpretations can be a nightmare-not to mention off the target of the intended purpose for the regulation. One soon recognizes the onerous characteristics of federal statutes. Another admonition the Lord gave those lawyers and pharisees back then was that they tended to strain at a gnat and swallow a camel! He meant that the pharisees were given to devoting themselves to the strict interpretation of law by writing hundreds of subrules or interpretation to law. In doing so they eventually lost sight of the original purpose of the law. I think they were being told, keep the law-but don't neglect to humanize it Keep it simple Recognize the purpose of why the law. "Mix in" a common sense approach. Someone once said, "Common sense is instinct -enough of it is genius." Today, as 2000 years ago, we need more "genius" displayed by legislators in considering the weightier matters of law. First of all true legislature genius calls for a declarative statement about the purpose of the statute and a fair, objective analysis of the ground rules by which it will be implemented. In the Health & Safety Act of 1969, the "findings and purpose" as set forth in Section 2 do define its purpose. I believe most of us affected can be in accord with the reasons advanced for the legislation. However, beyond those well-intentioned few paragraphs, we very quickly run into trouble. Congress complicated the simplicity of the statement of purpose by mandating government intervention into areas that cannot be effectively legislated, nor even should be legislated. The Act provided for broad gaged regulation which is unnecessary, inappropriate, and tremendously costly. Frankly, it detracts from a constructive, cooperative effort by the parties involved. These are strong negatives which characterize inappropriate legislation. Appropriate legislation and subsequent regulation, which is realistically conceived and practically enforced must be born of an honest desire for improvement, based on a working knowledge of common problems which are thoughtfully analyzed. Then the legislation must be written in clear concise language so that there can be little or no doubt as to its literal meaning and intent. To be practically enforced, it must be understood by all who will enforce it and by all who are subject to it. That is to say, an effective law or standard cannot be fixed or inflexible so that it cannot be tempered in human judgment. There must be an elasticity in the statute to provide for consideration of all of the relevant facts of a given situation. Such elasticity makes the compliance effort as meaningful as it can be for the time and dollars invested. Meaningful compliance requires room for common sense. Today, we in business along with our associates in government and labor, urgently need to pause, and assess our current situation. The problems arising from the 1969 Act have been intensified through the Mine Safety & Health Act of 1977. After reading the "findings and purpose" of this legislation, and by process of elimination, we should all clearly see what is and is not the purpose of the Act. 1) It is not to turn the management of private industry over to government. 2) It is not to impair the efficient operation of business. 3) It is not to reduce productivity and profits. 4) It is not to reduce national unemployment. 5) It is not to perpetuate the bureaucracy. 6) It is not to increase the tax burden on an already overburdened people. 7) It is not to increase our balance of payments deficit. 9) It is not to replace management/labor relations in working together to solve problems.

Jan 1, 1981

By E. V. Murphree

CREATION of atomic energy, aside from its influence on war or peace, has posed these basic questions for the world: How soon can energy from atoms be harnessed to do man's daily work? How much of this power will there be, to what degree will it supplant present fuels, and what does it imply for the future of civilization? Answers to these questions may be found in part in analysis of just what atomic energy is and how far its development has come. The answers are encouraging. One of the first questions encountered in considering the application of atomic reactions is whether such reactions can be controlled. Fortunately, this has been adequately demonstrated by the operation of the Government plutonium plants at Hanford, Wash. Here nuclear reactions are carried out on a large scale involving liberation of about a billion B.t.u. per hour. This hourly heat liberation is equivalent to that obtained from about 7100 gallons of fuel oil. It has been possible to operate these plants day in and day out with the reaction controlled at the intensity desired. There should therefore be no question that, under proper conditions, reactions involving nuclear fission can be controlled.

Jan 1, 1946

R. Trimble, Pittsburg, Pa (communication to the Secretary) : There are in the proposed specifications only two points on which I wish to comment at this time.

Jan 1, 1902

By E. G. Banks

THIS paper is presented in the belief that metallurgists and chemists will be interested in the practice of grinding in tube-mills in connection with stamps, especially since the records of working here given extend over a lengthy period of time (since May, 1905). The ore from the Waihi mine-more especially that produced in the upper levels-contains a large proportion of hard, chalcedonic quartz, and the gold exists in an exceedingly fine state, conditions which necessitate very fine crushing in order to ob¬tain a high extraction of the precious metal. Before the introduction of tube-mills at the 90-stamp Waihi mill, it was found necessary to stamp through 40-mesh (1,600 holes per sq. in.) woven wire-screens, having a fairly high discharge. The pulp then graded

Jan 1, 1907

Magazine Advertising $ 62,564 83 Magazine Sales 3,591 44 Total 66,156 27 Dues, Arrears 7,032 88 Dues, Current 96,839 74 Dues, New Members 6,525 00 Dues, in advance 1,907 02 Initiation Fees 7,584 00 Sale of Transactions 3,909 03 Sale of Binding .. 7,845 05 Sale of Special Editions 338 20 Sale of Year Book 76 20 Sale of Pamphlets 1,189 06 Sale of Authors' Reprints 867 54 Miscellaneous Receipts 62 93 Interest on Bank Balances 1,712 89 Interest on General Reserve Fund 337 50 Interest on Life Membership Fund 557 84 Interest on James Douglas Library Fund 5,491 89 Total Receipts $208,433 04

Jan 1, 1923

By Donald McLaughlin

INCREASING variety of interests among mining geologists is becoming more and more marked, as the frontier of their science and of its applications continues to expand. Each of the traditional lines of inquiry provides its crop of new and better defined problems, and answers to them are being found in far more precise terms than in the past as older uncertainties .are swept away with the sharper techniques and the even sharper ideas of modern geology. A glance over the assemblage of projects and publications in 1939 reveals conspicuous activity in many different parts of the front, such as the attack on the controversial question of the acid or alkaline character of ore-forming solutions, the place of mineral districts in the larger structural framework of continents, and the place of ore shoots in the local patterns of districts. Instructive comparisons are being made which cut across lines of older correlations or which reinforce them by pointing out heretofore ne-

Jan 1, 1940

By P. R., Bradley

THE Juneau gold belt is divided into ore-bands of poor definition. The most easterly workings on the , belt, those of the Alaska Gastineau Co., disclosed three separate bands: the Footwall or Ground-hog band, 70 ft. wide; the Perseverance band on which the recent mining was done, also 70 ft. wide; and the No. 2 band, 100 ft. wide. These bands, aggregating 240 ft., are found over a width of 2000 ft. Going toward the west into the adjoining Alaska Juneau ground, four bands have been found which have a total 'right-angle thickness of 755 ft. These bands are convergent in their westerly trend and terminate on the plane of Silver Bow fault. The four bands have better definition at the fault plane than at the eastern boundary line where they enter the property. -Along the property line, the width of the bands and intervening country is 1600 ft., and at the Silver Bow fault this width is reduced to 1300 ft. The distance from the eastern property line to Silver Bow fault is 2400 ft. The bands are slate or slate with metagabbro intrusions, together with gold-bearing quartz masses, stringers, and gash veins. The bands themselves are not all ore, but all commercial .ore is found within the bands. They have no uniform width either in horizontal or vertical section. The ore has no hard and fast boundary except where cut by faults, and profitable mining ceases on a vague and

Jan 1, 1929

By AIME AIME

THE 1941 fall meeting of the Iron and Steel and the Institute- of Metal, Division held at the Ritz-Carlton Hotel, Philadelphia, during the first three days (Oct. 20-22) of the National Metal Congress was well attended as usual, and the seven technical sessions and the joint round table on order-disorder transformations were this year of considerably more than routine interest. Despite unseasonably warm weather, a scarcity of hotels (there were rumors, apparently well-founded, that , some of the metal man attending the Congress had to stay in tourist camp), and a multiplicity of technical and other ions of the co-operating societies that gave the Congress this year the general air of a three-ring circus the A.I.M.E. sessions attracted audiences that ragged from seventy or eighty up to 350

Jan 1, 1941

By Frank Haas

THE public generally has-become aware that there is something wrong with the coal industry and a clamor has arisen for an explanation if not a remedy for this disorder. It is only reasonable that this Institute be looked to for a diagnosis to show the way for some other .agency to prepare the patient for prescription or operation. The subject is extensive, widely diversified, and beyond the efforts of an individual to cover completely; one of the objects of this paper is the initiating of a symposium on the non- technical factors essential to an understanding of the bituminous coal industry. The present condition of the coal industry cannot be described in a few words but, in effect, it resolves itself into a simple statement: The average coal operator is losing money notwithstanding a firm conviction on the part of the consumer that he pays too much for his coal. Without enumerating the many and varied. factors which contribute to this condition, this paper will be devoted to the interrelation of taxation and ownership of coal and its effect on finance

Jan 1, 1930

By William S. Springer

A NEW preparation plant has been put in - operation to treat coal from the recently opened Concord mine, located about 15 miles west of Birmingham, Ala., by the Tennessee Coal, Iron & Railroad Co., a U. S. Steel subsidiary. The mine produces metallurgical grade coking coal from the American seam for use as coke in the company's blast furnaces at the Fairfield and Enseley works. The capacity of the operation is 1000 tons of run-of-mine per hr, approximately half of which is delivered to the by-product coke plant at Fairfield after beneficiation to metallurgical grade. The remaining portion of the mine run is rock and refuse removed during preparation. No boiler coal or other fuels are produced by this mine. Preparation of the coal is done both under- ground and on the surface. The underground primary crushing station removes some tramp iron, and screens and crushes the oversize, most of which is rock, to protect the main slope conveyor. The surface plant consists of a crushing and screening plant, large blending bins, a two- process washing plant, a water clarification and

Jan 1, 1950

By J. L. SCHUELER

THE writer has reread Mr. Ingalls' interesting article in the July, 1923, issue of MINING AND METAL- LURGY on "The Use of Spelter in Galvanizing." It seems that most writers, in commenting upon coatings of spelter on sheets and wire, dwell upon the thin coatings which these materials carry, and rightly so. However, they seem to forget that until very recently, in the case of wire, the manufacturer did not know how to apply a heavy coating of spelter to the wire, especially if the wire was to be woven into fence or fabricated in some other manner, because heavy coatings of spelter are exceedingly brittle. This is even true in the case of high-grade spelter, but to a lesser degree than with Prime Western. Because of this brittleness, it has been necessary for wire manufacturers to smooth the coating by passing the wire through tightly compressed wiping means of some kind, usually asbestos. This removes all of the excess spelter and allows only a thin coating to remain. The latter, as a rule, is malleable and the wire can be fabricated without material injury to the coating.

Jan 1, 1924

By William B. Harris, Leonard Greenburg, Gustav Werner

Haulage in tunneling operations generally has been done with electric locomotives. As a rule, on short hauls the source of electricity is a storage battery mounted on the locomotive, which, of course, must be removed and recharged periodically. Where the distance from the recharging point to the tunnel face is very long, and where loads are heavy, trolley-driven locomotives are used. Diesel engines have been used in mining and tunneling operations in Europe for a number of years. The recent reports of studies in Belgium1 and by the Bureau of Mines in this country2-4 have indicated the potentialities of this form of power for haulage, mucking, bulldozing and many other underground operations. The hazards attending the use of Diesel engines in more or less closed spaces have long been known. The exhaust constituents that may create a harmful or objectionable environment are carbon monoxide, oxides of nitrogen and sulphur, carbon dioxide, aldehydes and smoke. Lack of precise information regarding the concentration of these gases and the ventilation requirements to reduce them to safe levels has to some extent suppressed their general acceptance in tunneling and mining work. Not until the work of the Bureau of Mines referred to above, and certain experience gained in the construction of the Delaware Aqueduct, ‡ has there been available the requisite information regarding the conditions under which their use may be permitted. This paper concerns itself with the successful operation of Diesel engines underground in the construction of certain parts of the Delaware Aqueduct, and describes the conditions under which Diesel engines have been found to operate with a minimum production of noxious gases. The test data reported were obtained during the operation of Diesel engines over a period of two years.* Studies by the New York State Department or Labor Exhaustive tests were made by the Division of Industrial Hygiene, of the composition of the exhaust gases given off by a Diesel engine mounted on a test block. These tests showed that certain' quantities of the gases are discharged from the exhaust. On the basis of these figures, preliminary requirements of design and control

Jan 1, 1943

By Gustav Werner, Leonard Greenburg, William B. Harris

Haulage in tunneling operations generally has been done with electric locomotives. As a rule, on short hauls the source of electricity is a storage battery mounted on the locomotive, which, of course, must be removed and recharged periodically. Where the distance from the recharging point to the tunnel face is very long, and where loads are heavy, trolley-driven locomotives are used. Diesel engines have been used in mining and tunneling operations in Europe for a number of years. The recent reports of studies in Belgium1 and by the Bureau of Mines in this country2-4 have indicated the potentialities of this form of power for haulage, mucking, bulldozing and many other underground operations. The hazards attending the use of Diesel engines in more or less closed spaces have long been known. The exhaust constituents that may create a harmful or objectionable environment are carbon monoxide, oxides of nitrogen and sulphur, carbon dioxide, aldehydes and smoke. Lack of precise information regarding the concentration of these gases and the ventilation requirements to reduce them to safe levels has to some extent suppressed their general acceptance in tunneling and mining work. Not until the work of the Bureau of Mines referred to above, and certain experience gained in the construction of the Delaware Aqueduct, ‡ has there been available the requisite information regarding the conditions under which their use may be permitted. This paper concerns itself with the successful operation of Diesel engines underground in the construction of certain parts of the Delaware Aqueduct, and describes the conditions under which Diesel engines have been found to operate with a minimum production of noxious gases. The test data reported were obtained during the operation of Diesel engines over a period of two years.* Studies by the New York State Department or Labor Exhaustive tests were made by the Division of Industrial Hygiene, of the composition of the exhaust gases given off by a Diesel engine mounted on a test block. These tests showed that certain' quantities of the gases are discharged from the exhaust. On the basis of these figures, preliminary requirements of design and control

Jan 1, 1943

By S. R. Mitchell, M. Weissman, J. H. Brown

It has been demonstrated that for fine grinding operations, the energy input (E) and the product size modulus (k) are related by an equation of the form E = Ak1-n (1) where "A " and "n" are constants.(1) Also, it was suggested that "A" is determined by the comminuting device and that "n" depends primarily on the rock. It was the purpose of this investigation to study these constants by determining the form of an energy-size reduction relationship over an extreme range of energy inputs, and at the same time, to evaluate the minimum particle size produced during grinding. The comminution system consisted of a stainless steel laboratory ball mill in which quartz was ground at 60% solids for times ranging from 1 minute to 700 hours. The mill which measured 10" diameter by 12" long was loaded with about 60 pounds of balls ranging in diameter from 3/8" to 1-1/8" and was driven at 55 r.p.m. Quartz was selected for the tests because it is a brittle material for which size distribution data were expected to show a constant distribution coefficient regardless of product size.(1) This permitted specification of product size by a size modulus alone. The quantities measured were the time of grind (measure of energy input) and the specific surfaces of the products. Since no accurate method is available yet for determining particle size directly in the very fine size ranges specific surface data were used for this purpose. The relationship between these two quantities may be expressed as where Cis a constant which includes a shape factor, p is the specific gravity of the solid,_S is the specific surface and D is an equivalent particle diameter. For a material in which the distribution coefficient does not change with size the term (l/S) may be substituted for k in equation L if the proportionality constant "A" is changed correspondingly. This substitution was made in this work but in addition, screen analyses were made on several products to verify the equivalence of the two methods of size specification. EXPERIMENTAL DETAIL QUARTZ Quartz from two sources was tested. One series of tests was made on a clear, high purity crystalline quartz from Brazil and Arkansas, and another series was run on massive quartz fromNewHampshire. Grinding charges of the high purity material consisted of 2000 gram samples of -3-8 mesh particles, while the charges of the New Hampshire quartz were 500 gram samples of a -35+48 mesh screen fraction. The difference in the sizes of these two series of charges was not significant in view of the extreme size reduction accomplished, and the New Hampshire samples were smaller to permit ginding to finer sizes in shorter times than required for 2000 gram lots. SAMPLING AND ANALYSIS Separate charges were ground for all tests in which the grinding times were less than one hour and for all tests on New Hampshire quartz since these products were difficult to sample accurately without affecting the entire charge. During the long time grinding tests the mill was

Jan 1, 1961