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By F. E. Bash

WHENEVER electric and open-hearth steel men discuss the relative advantages of their respective methods, the question of temperature is always discussed, so that this paper is written in the hope that definite data may settle some of the questions and encourage further investigations along these lilies. The writer has had the opportunity of taking the tapping temperatures of steel from electric furnaces of different sizes in various plants and from a number of open hearths handling the same kind of steel. All temperature measurements were made with the same disappearing-filament type optical pyrometer and the corrections for emissivity applied were those worked out by Burgess,1 which are 0.40 for steel streams and 0.65 for slag. The correction is applied by calculating the curve giving the relation between the true and apparent temperature in the following formula: Log E = CZ log e( 1 _ 1 x \T2 T1) in which E = emissivity; C2 = 14,500; e = base of Napierien logarithms; ? = wave-length of light used = 0.65/4; T2 = true temperature, in degrees absolute; T,1 apparent temperature, in degrees absolute. The curve showing the relation between true and apparent temperature for steel and slag arc given in Fig. 1. For the purpose of comparison of open-hearth and electric furnaces, there are given in Table 1 the tapping temperatures of two 25-ton Heroult electric furnaces and one 6-ton with one 50-ton acid, one 40-ton basic, and one 65-ton acid open-hearth furnace, all making nickel ordnance steel for guns. The two 25-ton Heroult electric furnaces were finishing steel refined by the triplex process and the 6-ton Heroult finished steel that was partly refined in an open hearth.. In this table, the tapping temperature and the temperature of the steel stream into the first ingot

Jan 9, 1919

By C. E. Mendenhall

FOR the purpose in hand, pyrometry may be taken to include all temperature measurements from, say, 200° C. to the highest attainable, especially when considered from the technical or applied side. It will be convenient first to consider the entire content of a course of study grouped under the headings of the various methods of measurement, which are quite distinct in principle and involve different equipment. Brief suggestions will be given under each heading, and the summary will be followed by comments on the purpose of such a course and methods of conducting it. 1. Expansion and pressure methods: mercury thermometers (glass and quartz), liquid, gas, and vapor-pressure thermometers, especially recording instruments. Especial attention should be given to the limitations of these methods, which, particularly in high-temperature mercury thermometry, are often overlooked. Range approximately to 700° C. 2. Resistance thermometers: both bridge and potentiometer methods, of indicating and recording. Calibration; lead compensation; design of thermometers for special purposes. Range to 1200° C. 3. Thermoelectric pyrometers: potentiometer and deflection methods indicating and recording. Calibration, leakage errors, contamination errors, base and noble couples. Range to 1500° C. 4. Total radiation methods: thermoelectric, resistance, and expansion indicators, mirror and lens collectors, calibration, permanence of characteristics, absorption errors. Range, to highest attainable temperatures. Methods of producing perfect radiators-true, and virtual or "black body" temperatures. 5. Partial radiation methods: absorption and spectroscopic methods of getting partial radiation, various comparison sources, polarization, electric, sector, and absorption methods of controlling intensity (Morse, Lummer, and Wanner types). Calibration, permanence of calibration, absorption errors. Methods of producing perfect radiators -improvised methods; true, and virtual or black-body temperatures.

Jan 9, 1919

Book Review Mexico, TODAY AND Tomorrow. By E. D. Trowbridge, Detroit. The McMillan Co., New York, 1919, 353 pp., 7;2 X 5 in. $2.00. The first eight chapters are devoted to an historical narrative of the Mexican peoples from the earliest times to the close of the war with the United States in 1345. "In dealing with events antedating what may be termed modern Mexico" the author has "made no attempt at original research, and so far as concerns anything prior to 1900, the work here presented is a repetition, a reflection, of the findings of opinions of Fiske, Prescott, Bancroft, Luis Perez Verdia and other authorities." The remainder of the hook deals with Mexico during and since the Diaz regime. It is interesting throughout but is not always convincing or consistent. Social conditions are described in a way illuminating and possible only to one who is familiar with the peon and his hitherto seemingly hopeless position in reference to the wage system and church oppression. In fact, the author makes the hold accusation that the "primitive rather than immoral" condition of the peons in the matter of their marital relations is due to the disregard of the church for their welfare and capabilities. The true accounts of the Madero revolution and the Huerta regime read like fascinating medieval fiction. The reason given for men remaining in the Madero army is still the controlling one regarding any of the armies there. "They had horses, arms, all the food they wanted, money to spend and no work." The discussion of Mexican financial schemes is wholly from the Carranza viewpoint. To meet a monthly deficit of ten million pesos the author says "the government forced loans from the National Bank, and Bank of London and Mexico, and repeated the operation several times, finally practically exhausting their bullion and cash reserves. Hostile foreigners refer to this operation as the looting of the hanks! Drastic as this action was, there was good ground on which to justify it." However, that necessity knows no law is never an acceptable tenet except to him who applies the screws. The discussion of the economic problems and their solution is rather chimerical and presupposes a civil and national virtue in the present government not discernible except to one ultra friendly. The book is an interesting exposition of the very much involved situation from the viewpoint of approval of both the Carranza government and the attitude of the United States in its dealings with him. The editing of the book leaves something to he desired. P. E. B.

Jan 9, 1919

By C. H. Mathewson

THIS paper was prepared upon request as a contribution to a symposium covering the manufacture, properties, and uses of the important non-ferrous metals. In approaching a subject as broad as this, there is a natural desire to build up a comprehensive and finished production which shall constitute a dependable source of information on all questions properly belonging to this branch of metal technology. There are, however, a number of circumstances, apart from the mere routine of labor and thought involved, which operate rather effectively against the possibility of completing such an ambitious program at the present time. First of all, as far as any public record of results is concerned, the commercial rolling, drawing, and forming of zinc with relation to changes of structure and properties-and this we consider to constitute the elements of metal technology-might as well be an unpractised art. We have never seen a published photomicrograph showing the structural characteristics of either hard or soft sheet or strip, although the structure of castings has been frequently described, and other coarse-grained structures resulting from hard-hammering and annealing have been reproduced. Thus, an author in this field must proceed to his task without much assistance from the literature, and the outcome can represent only a personal estimate of principles, facts, or findings, and not a summary

Jan 9, 1919

By C. B. Thwing

IT is likely that among most races, owing to the ease of finding and working clay, the making of clay utensils was learned earlier than the molding of metal implements. The ancients made good pottery and durable brick in kilns that wasted fully one-half the heat and spoiled fully one-fourth of the ware; and, taking the clayworking industry as a whole, we are doing the same today. The chemical and physical changes involved in the burning of clay are so many and vary so much with the composition of the clay that it is not surprising that the rule-of-thumb methods so commonly employed fail to give uniform results. In its passage from plastic clay to the vitreous or stonelike character the mingled minerals and accidental organic impurities of which the clay is blended must pass through four stages, the second and third usually overlapping, and the fourth often beginning before the third is complete. These stages in their order with the rising temperature are drying, dehydration, oxidation, vitrification. In the first part of the drying stage, usually accomplished in part outside the kiln, the water mixed with clay is dried out at temperatures not much exceeding the boiling point of water. In the later part of this stage, within the kiln, the hygroscopic water, absorbed from the air is expelled at somewhat higher temperatures, this stage being known as watersmoking. Some clays are very sensitive to temperature during the drying stage and if the temperature exceeds 100°, the ware becomes checked. Other clays may be dried more rapidly without danger. In down-draft kilns, the draft is slight during the watersmoking stage and the water driven off from the top rows condenses on the ware in the bottom of the kiln, with the result that high temperatures are likely to be reached at the top of the kiln before the bottom is fully dry. The lag in temperature of the bottom persists to the second stage in spite of the better draft then prevailing.

Jan 9, 1919

By I. C. White

ONLY two factors appear to be directly responsible for the geographic distribution of sulfur in the coal fields of West Virginia, these, are the FIG. 1. stratigraphic position of the coals in question., and the eastward or westward location of the deposits. There appears to be a progressive increase in the sulfur content of West Virginia coals from the oldest Pennsylvanian deposits in the Pocahontas, New River, and Kanawha Groups of the Pottsville Series up through the Allegheny, Conemaugh, and

Jan 9, 1919

By Reinhardt Thiessen

UNDER sulfur in coal, is usually understood that form of sulfur which is combined with iron and known as pyrite. It occurs in the form of halls, lenses, nodules, continuous layers, thin sheets, or flakes, both in horizontal planes and vertical cleavage fissures. But pyrites also occur as very fine microscopic particles, or nodules, disseminated through the compact coal. This form has had but very little consideration. Finally, there is sulfur in coal in an amicroscopic form (not visible with an ordinary microscope), probably combined with the organic matter that exists -in tile coal. This form has had considerable attention from a scientific standpoint, but has probably not been recognized enough on the economic side. One or the other, or both, of these two latter forms may comprise the larger part of the sulfur content of coal, especially after it has been washed or otherwise prepared for use.

Jan 9, 1919

By J. A. Ede

THE object of the writer is to call attention to a rather unique aggregation of economic products distributed over a line of succeeding formations about 3 mi. long, to be seen within a few miles of La Salle, Ill. Fig. 1 is an ideal section of the stratification exposed and exploited along a distance of 3 1/5 mi. in a southwesterly direction from the quarry of the Utica Hydraulic Cement Co. located near the historic site of Kaskaskia village to the Oglesby, shaft at Oglesby. No attempt has been made to cover the whole field, special mention only being made (with the exception of two places) of the operations found along the course or parallel to the direction assumed in the ideal section. I have used Fig. 2, after J. H. Bent and De Witt Kelly, to locate the relation of the La Salle anticline to the coal mines of this district and to show the operation of No. 1 and 3 mines of the Illinois Zinc Co.

Jan 9, 1919

By C. W. Parmelee

THE ideal fuel for burning ceramic wares is the one that, among other characteristics, has little or no sulfur. For that reason wood was long considered the most desirable fuel but its high cost has practically eliminated its used except in regions where it is very abundant or other circumstances warrant its choice. The fuels commonly employed are natural and producer gas, oil, and coal. The last named is undoubtedly the most important, not only in this country but abroad. Occasionally anthracite is used but the larger part is bituminous. The quality of the coal used depends on the kind and the value of the products being manufactured. For some materials, such as common brick, hollow block, etc., the quality of the coal is of less importance than in the manufacture of polychrome terra cotta, pottery, porcelain, etc. It is obvious that in burning clays that contain notable amounts of pyrite, marcasite or gypsum, as is the case with many common clays, the sulfur content of the fuel is of much less importance. The permissible amount of sulfur in the coal used will depend on the kind of product being manufactured. "A good sample' of coal commonly used in pottery ovens has something like this quantity of sulfur." PER CENT. Total sulfur 1.20 Sulfur in the ash 0.11 Volatile sulfur a 1.09

Jan 9, 1919

By Leo Dana

As a part of an investigation conducted by the Cement Section of the Bureau of Standards, at the plant of the Security Cement & Lime Co., Security, Md., the High-temperature Measurements Section was called upon to measure temperatures in a dry-process, coal-burning kiln. Although the measurements were made only under the conditions existing in one plant, the methods employed and the conclusions drawn apply, in a general way, to those existing in most plants. As far as we have been able to learn, no sufficiently thorough methods of making accurate pyrometric measurements in the sintering zone and in the rear end of rotary cement kilns have been described. It is believed that in this investigation, data were obtained that can serve as a foundation for further study of the problems of pyrometry in cement kilns. IMPORTANCE OF TEMPERATURE MEASUREMENTS IN ROTARY CEMENT KILNS The manufacture of Portland cement is today fairly well standardized. The various steps in the manufacture have been developed to such an extent that the process is almost automatic. In spite of these strides the efficiency of utilization of heat in the kiln is very low and an undue proportion is wasted; for example, about 50 per cent; ordinarily goes up the stack. In order to prevent these losses, not only should means be provided to utilize the waste heat but instruments, such as pyrometers, should be installed to study and control the operation with the view of minimizing the losses. At the same time, such control will produce a more uniform product. The saving in-fuel that may be effected by the proper use of pyrometers would be much more than their cost. Where these pyrometers should be installed and what they can show are very briefly indicated in the following paragraphs and discussed in greater detail later.

Jan 9, 1919

By Paul Foote

SEEBECK discovered, in 1821, that if, in a closed circuit of two metals the two junctions are at different temperatures, an electric current will flow in the circuit. In the case of an iron and a copper wire, for example, current will flow from copper to iron at the hot junction, or from iron to copper at the cold junction. Two factors combine to cause the current. An electromotive force exists between the two metals, the magnitude of which, depends upon the temperature and upon the metals; this is called the Peltier e.m.f. If a single wire of homogeneous material is heated at one end, an electromotive force is developed between the ends of the wire, the magnitude of which depends upon the metal and upon the difference in temperature; this is known as the Thomson e.m.f: The total e.m.f. acting in the circuit is the sum of the Peltier e.m.f. at the two junctions and the Thomson e.m.f. in each wire, consideration being given, of course, to the algebraic signs of the four e.m.f.'s. The total electromotive force thus depends upon the difference in temperature of the two

Jan 9, 1919

By Herbert Ives

THE incandescent gas mantle is of considerable interest from the standpoint of temperature measurement because it presents a series of apparent contradictions to the established laws of radiation on which are based some of our best methods of temperature determination. One of these contradictions is that the mantle of least brightness (of the commercial thoria-ceria group) is the one having the highest temperature; this, though explicable without any violation of radiation laws, was long a stumbling block to the understanding of the performance of the mantle. Another anomaly is that the energy radiated by the mantle decreases with the rise of temperature, thus apparently invalidating total radiation methods of pyrometry, based on the fourth-power law. The discussion of methods of measuring mantle temperature which follows, is largely taken from an extensive study of the physics of the Welsbach mantle. 1 The incandescent gas mantle consists of a skeleton of refractory oxide of very light weight and open structure, formed by the ignition of a cotton or silk "stocking" previously thoroughly impregnated with salts of certain rare earths. The mantle of commerce is a mixture of approximately 99 parts of thorium oxide with 1 part of cerium oxide. This mixture, discovered largely by accident, gives luminous radiation many times greater than that from either of the constituents taken alone. It is customary to speak of the thoria as the "base" and the ceria as the "colorant," and the commercial mantle represents one of a family in which an oxide of low emissive power is employed as a base, which will assume a high temperature, while a small amount of some other oxide of high visible emissive power is added, which will reduce the temperature of the mantle but little. This is, in general, the most efficient- way, from the standpoint of visible emission, to utilize a substance of high emissive power in the visible spectrum. But it is not necessary. that two substances should be employed to produce a radiator

Jan 9, 1919

On an average of at least once a year there comes to the attention of the Institute Headquarters the activities of some individual who represents himself as a member of the Institute, and by a hard-luck story or other means secures loans or advances of money which are never returned. On one or two occasions the Institute has been able to secure the arrest and conviction of these frauds. Recently some individual has been operating in California and defrauded several members of the Institute. He is described as a man of 5 ft. 7 or 8 in. height, decidedly slim, and his weight is about 140 lb. His hair and mustache are gray, eyes blue or gray and he claims to be near-sighted. He is also said to have had a keen, furtive, "Hang-dog" look and claims to have been raised in Bethlehem, Pa. He speaks with a German accent. If a man answering this description presents himself before any members and claims to be a member of the Institute it will be to the good of the profession if he can be caught making fraudulent representations and placed where his ability to defraud will be under control. The most effective means of apprehending persons of this character is the very prompt notification to Institute Headquarters of any persons claiming to be members of the Institute in hard luck. If such persons are asked to supply their signature or photograph or both to be, forwarded to Institute Headquarters for identification this will serve as an excellent check on their operations. Reluctance to comply with such a request is in itself a suspicious circumstance.

Jan 9, 1919

By John Goheen

RECENTLY the head burner at a brick. plant with over 40 years' experience said that he had burned brick by guess for over half his lifetime and had used pyrometers for 2 1/2 years but hoped that he would never have to burn kilns without pyrometers again. The ceramic engineer in making a special study of the burning of clay ware and the effect the heat of the kiln has on color and vitrification is also rapidly placing the burning of clay on a twentieth-century basis. Clay ware may be divided into various groups, brick and drain tile; sewer pipe; firebrick; and pottery, which, in turn may be subdivided into special classes. As nearly as the analysis of the clay type of kiln, etc., will allow, there are practically the same problems to solve in burning in all of the processes or operations. The underlying objective is the same, namely the production of the best grade of ware under the most efficient and economical manufacturing system. The principal problem in the production of clay ware is the burning off of the kilns. The most modern steam shovel may dig the clay and the most advanced types of pug mills and wire cut machines or molds of various kinds may be installed, but unless the drying and burning of the ware is successful, all of the previous operations will be useless. On this final operation depends the entire result of the plant. In reality, burning of all. clay ware is purely a heating proposition. The kilns, or furnaces, should be so designed as to give equal distribution of heat. Consequently, the problems of design and construction of kilns to produce equal distribution of heat require serious consideration, as do also the questions of heat control and draft control. The three most important factors in the burning of practically all types of kilns may be

Jan 9, 1919

By F. W. Robinson

THE temperature coefficient of electrical resistance of pure metals is high and therefore the resistance increases rapidly with rising temperature. In 1871, Siemens suggested the use of this property as an accurate means of temperature determination. Owing to practical difficulties, particularly the contamination of the metal and consequent permanent change in its resistance and its resistance-temperature relation, this method fell into disrepute as a practical standard until revived later by Callendar and Griffiths, and subsequently by Holborn and Wien, all of whom showed that the earlier difficulties were not inherent in the method but incident to the mode of protection of the resistance coils. Following .the work of these investigators, the problem of temperature measurement by this means has been the subject of careful study and has now assumed an importance second only in practical adoption to the thermo-electric method. It is generally recognized, both here and in Europe, that the standard temperature scale should be the thermodynamic as it permits the evaluation of high temperatures on the basis of the radiation laws of Stefan and Bolzmann, of Rayleigh, and of Wien and Planck, on a scale consistent with that obtained by means of the gas thermometer at low temperatures. Lord Kelvin showed that only. a very small correction, amounting to about +0.7° at 1000° C.-almost within the limits of experimental errors-is necessary to adjust the constant-volume nitrogen thermometer to the ideal thermodynamic scale.

Jan 9, 1919

The fall meeting of the Institute of Metals Division Will be held in Philadelphia on Sept. 30 to Oct. 2. All meetings will be held in the Ritz-Carlton Hotel, Broad and Walnut Streets, which is also the hotel headquarters. As this meeting is being held in conjunction with the meeting of the American Foundrymen's Association, the members of the Institute will have the privileges of the exhibit of the Foundrymen's Association. This, it is expected, will be one of the largest exhibits made in this country. On Monday evening, Sept. 29, there will be a meeting, in the Ritz-Carlton Hotel, of former officers and members of the Executive Committee of the Institute. It is requested that all officers and Committee members, the present as well as the past, will arrange to be present.

Jan 9, 1919

By N. E. Bonn

IT is well known that most of the materials entering into the manufacture of thermocouples are subject to variations in their thermoelectric characteristics, the chief causes of which are: differences in chemical composition; the previous .history, which includes mechanical working, ageing, oxidation, and contamination; and mode of use, such as depth of immersion, etc. In the case of a very extensively use thermoelement, the iron-constantan couple, neither iron nor constantan are absolutely uniform, and a number of checks are made during the process of manufacture. As both are subject to diversion from a standard value, neither, can be used for checking the other. It is, therefore, necessary to find a third metal against, which iron and constantan maybe checked. It was to find such a metal; that the present investigation was undertaken. To be a reliable, checking standard, the metal must possess a fairly high melting point? it must be obtainable in sufficient purity, and it must be uniform and constant with respect to its thermoelectric qualities. The choice is, as a result, limited to a few metals, such as copper, gold, and silver. Copper has the advantage of low cost, which makes it possible to use each wire only once and thus avoid any variations due to continued use, although previous investigators have found1 that continued use does not affect the calibration of a copper-constantan thermocouple. Copper also has the advantage of a large thermal electromotive force against constantan and would be desirable as a checking standard if it could be shown that it possessed the proper thermoelectric characteristics. The investigation, accordingly, resolved itself into three phases: the uniformity of commercial electrolytic copper, the effect of aging and method of annealing, and the calibration of the copper-constantan thermocouple.

Jan 9, 1919

By J. M. Lohr

THE characteristics and uses of thermocouples of platinum and the platinum alloys being so well known, this paper will be confined to base-metal couples. During the past decade, there has developed a strong demand for thermocouples made of metals cheaper than the platinum alloys, and suitable for industrial heat measurements. Much research has been clone but only a very limited number of alloys have been found to possess the necessary characteristics for general technical use. In the development of thermocouple alloys it is necessary to consider the following points: The electromotive force and temperature relations; permanency or constancy; reproducibility; manufacturing difficulties; durability; and accuracy in use. The electromotive force developed by the thermocouple should increase with the rise of temperature according to some definite law. It is desirable that the electromotive force should vary directly with the temperature difference of its junctions, in other words, giving a curve linear or nearly so. It is also desirable that the resulting electromotive force be as large as possible for any given range of temperature, thereby insuring greater accuracy of readings.

Jan 9, 1919

By R. L. Frink

I FEAR that my treatment of this subject may not, in all instances, meet the approval of those who read my opinion as to the utility and efficiency of pyrometers in the making of glass, or bottle-glass. It may be superfluous for me to add that this opening statement is based on over 15 years' experience in an endeavor to successfully apply pyrometers, or heat-measuring instruments, to glass-melting furnaces, particularly the type known as tank-furnaces, and that such endeavors have proved more or less futile. It is my desire, therefore, to herein set forth the problems encountered, hoping thereby to stimulate further effort in the successful application of pyrometers. It is my desire, also, to invite criticism of the methods used and suggestions from those who may have a wider experience, or who may have better methods. Fin. 1.-GLASS TANK FURNACE. In general, I believe that the inefficient application of pyrometry to the melting of glass in tank furnaces is not due as much to the instruments as to the conditions under which they must be used and the character of the medium in which they must reside. Most of those present no doubt, are familiar, at least in a general way, with the methods and apparatus used in the melting and making of bottle-glass, or glass that is formed into containers of various shapes and designs. Most of this glass is made in what is known as a tank furnace, these furnaces vary widely in design and construction. In general, they consist of a rectangular tank-like form, built up of fireclay blocks, and range from 2 by 4 ft. (0.6 by 1.2 m.) to 24 by 140 ft. (7.3 by 42.6 m.) with a depth of glass from 2 to 5 ft.; or a capacity of from approximately. 2 to 700 tons. Fig. 1 shows the general

Jan 9, 1919

The following communication was recently sent President Wilson by J. Parke Channing, Chairman of the Engineering Council: The transportation systems of our country are largely the creations of its professional Engineers. This statement can be made without disparagement to the statesmen, the financiers, the manufacturers, the lawers, the educators, the mechanics, the laborers and many others, who, with the Engineers, have contributed to the development of transportation. Through all stages of preliminary exploration, final survey, construction, upkeep and operation, in financial management, and in adjustment of the relations of transportation to the public, the genius and knowledge of the Engineer are essential. Not only in technical physical matters, but also in determinations of policy, his contributions have supplemented and must ever supplement those of other men. These declarations hold good for all the carriers of commerce, by rail, by highway, by water, by pipe-line, by wire, or by air. Hence, it follows that the body established by Government to regulate the commerce, the carriers and the ways of communication, embracing so many engineering features, should number among its nine members, men of engineering training and experience. Engineering Council, being aware of a vacancy on the Interstate Commerce Commission, begs leave to request the Chief Executive that in filling this vacancy, he give earnest thought to the selection of a man who, to his other qualifications, adds the training and experience of an engineer familiar with transportation problems.

Jan 9, 1919