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By A. M. Gaudin

TEN years ago Taggart, Taylor and Ince1 described a workable, convenient apparatus for the measurement of contact angles be-tween cleaved, ground or polished particles and captive bubbles. Wark and Cox2 and Wark and Sutherland3 have done an im-mense amount of experimental work with this apparatus. Their work has had as principal object the determination of "con-tact curves." Contact curves are Cartesian charts in which pH (or some other variable) is plot-ted against quantity of modifying agent. The rectangular area is broken into two or more curvilinear areas separated by the contact curve. The curve indicates that a sharp demarcation exists between condi-tions that bring about sticking of particles to bubbles and conditions that do not pro-duce sticking, The type curve appears in the TRANSACTIONS as Fig. 1, page 248, volume 112. Wark and Cox offer data to show that the contact angle has a value determined by and characteristic of the agent used. Wark and Cox also make the statement that they believe this value is independent of concen-tration (ref. 2a, p. 209), They say: It is suspected that, given sufficient time and provided that there are no disturbing factors. the full ethyl xanthate angle (corresponding to a complete xanthate film) would be obtained in every case where contact occurs.

Jan 1, 1940

By R. T. Keyes, R. B. Clay, L. L. Udy, V. O. Cook, M. A. Cook

Based on compressibility and stress wave velocity in rock, initial explosive loading conditions, the thermochemistry of the explosive and reasonable description of the pressure-distance relations behind the shock front, the distribution of energy between the products of detonation and the burden are estimated as a function of time for various loading conditions. These include 'powder factor', loading density A (fraction of borehole occupied by explosive), and the explosive itself. Factors responsible for rock fragmentation are discussed in terms of: 1) 'release wave fracturing', 2) 'shear wave fracturing', and 3) 'release of loading fracturing' or 'rock bursting'. Release wave fracturing appears to occur only in the immediate vicinity of free faces, and shear wave fracturing only adjacent to the borehole under normal blasting conditions. Rock bursting is thus considered to be the most important means of rock fracturing in blasting. Means for maximizing it are considered. The most important factors to consider include maximum available energy A, explosive density p1, loading density A and 'powder factor'. Maximum efficiency is attained in general by maximizing the A . p1 product. This is achieved by using high density explosives at a loading density of unity (A = 1.0). Ways for achieving this condition are discussed. The bulk-handled aluminized slurry blasting agents have the desired properties for achieving optimum conditions for high blasting efficiency based on the theory outlined herein. Factors considered most important in the blasting of rock are: 1) The maximum available energy A, determined by the heat of explosion Q and the mechanical efficiency ?, a factor intimately associated with the mode of application (A = Q at highest gas concentrations). 2) The 'borehole pressure', pb, or the maximum pressure developed in the borehole after passage of the detonation wave and before the burden has had time to move or become compressed appreciably. (Owing to the short duration of the detonation wave at any particular point in the borehole, the fact that the explosive may not always fill the borehole completely and the further fact that the burden may not actually see the detonation pressure, the borehole pressure is considered more significant than the detonation pressure p2 as a performance factor in borehole blasting.) The borehole pressure is determined by the explosion or adiabatic pressure, p3 , and the loading density, A, or the fraction of the borehole filled by explosive. 3) The physical conditions important in the application of the explosive are: a) The 'powder factor,' (We/Wr), or the ratio of the wt of the explosive to that of the rock being blasted expressed as lb per ton or more generally in lb/cu yd. b) The bulk density, p1 ?. c) The 'burden' or 'line of least resistance,' the spacing between boreholes, the geometry of the borehole pattern and sequence of firing. d) The physical and chemical properties of the rock, most significant of which are possible heterogeneties, such as faulting, prefracture, and greater than micro-scale chemical heterogeneities. (This factor is not considered here but deserves a great deal of careful consideration.) All of these factors need to be carefully considered in the most economical engineering of a blast. Here is considered firstly an outline of the present status of dynamic rock mechanics, particularly as it pertains to blasting. The factors pertaining to the most efficient application of blasting agents are also considered, followed by a discussion of methods of application to achieve optimum explosives performance. ROCK MECHANICS Dynamic rock mechanics is currently a rapidly developing science contributing greatly to a better understanding and consequently the more effective application of explosives in blasting of rock.1-22 Basic to the development of the science of dynamic rock mechanics were the advances of Goransen23 and the Los Alamos and NOL groups24-28 concerning rock and stress wave phenomena and the transmission and reflection characteristics of stress waves at interfaces between different media. Basing considerations on this new knowledge as well as new experimental methods of study (ultra-high speed streak and framing cameras and electronic timers) the theory of fracture and failure of solids under impulsive loading by stress waves developed rapidly.14,16,27-29 Also the

Jan 1, 1967

All the Affiliated Student Societies report that the present college year promises to be a most successful one. The officers for this year, so far as reported, are as follows: TUFTS COLLEGE CHEMICAL SOCIETY President, CHESTER B. PIERCE Vice-president, JOHN H. SCHMUCK Secretary-treasurer, DANIEL A. PRESCOTT President, R. G. SATTERLEY Third vice-president, H. E. BLAKE First vice-president, LESTER VOCKE Secretary,-J. E. FLANIGAN Second vice-president, `V. J. KLINE Treasurer, PROF. JAMES FISHER, JR About 75 per cent. of the students are ex-service men, and most of them saw service in France.

Jan 12, 1919

By O. C. Holbrook, George G. Bernard

A new theoretical treatment has been obtained for the behavior of pattern waterflood injection wells when closed in. Two cases are treated: Case I where oil and water are assumed to have the same properties, and Case 2 where they arc different. In applying the method, one plots log (p — p,) vs closed-in time, where p is well-bore pressure at any tims and p, is static pressure. The value of p. is determined by trial and error as that value which makes the plot linear at large time. A value for the permeability-thickness product can be determined from the intercept of this linear part, and a value of the skin factor from the injection pressure at time of closing in. Application of the method to data from water floods at three fields seems to give reasonable results. For the case of unit mobility ratio, it is proved that this new method should give the same value for permeability-thickness product as the conventional pressure build-up method. In addition, the new method gives correct values for static pressure, whereas the conventional method does not, often indicating negative static pressures. The new method may be used in cases where the surface pressure persists after closing in as well as in cases where it does not. INTRODUCTION It is of considerable interest and importance to be able to determine the characteristics of the reservoir in an area surrounding a water injection well. Thus, if we can determine early in the life of an injection well that there is a considerable "skin effect", remedial measures can be started before a full-scale pattern flood begins. Similarly, if it can be shown that a gradual buildup of skin effect is occurring with time, measures to free the water of plugging material can be taken. Determination of static pressure in the water-injection well may show that the water is entering a thief zone and not the desired reservoir. Finally, determination of the permeability of the sand around the injection well will allow estimation of the future relation between injection pressure and rate. It should be possible to determine average reservoir permeability, skin effect and static pressure from pressure fall-off data. However, at the time we began work on this subject, it was thought that no adequate theory on which to base such determinations' was available. According to the conventional method which considers the reservoir to be filled with one fluid of small compressibility (see Van Everdingen, Joers2, and Nowak2), shut-in pressure is plotted vs log where is injection time, and At is closed-in time. The physical significance of injection time, may well be questioned in this case, since in a reservoir completely filled with a single fluid (as required by this theory) and with input and output rates equal, the pressure behavior after an initial transient is independent of t,. Attempts by our Tulsa area to use this theory led to negative values of static pressure in most cases. Because of these limitations of the method discussed above, it was decided to attempt to develop a new theory of pressure behavior in water injection wells, one which would apply when there is a gas saturation, as is so often the case in water floods. In the following treatment the assumptions and basic equations are given first, then the method of application of the equations. A complete example is given to clarify details of application. All difficult mathematics has been placed in the appendices so that the reader can follow the text without difficulty. However, if he wishes only to apply the results without knowing the basis for them, he can learn how to do this from reading only the sections entitled "Plotting of Experimental Results" and "Example." ASSUMPTIONS AND BASIC EQUATIONS Statement of Problem It will be assumed that a horizontal layer of constant thickness contains in its pore system a mixture of oil, gas and water. While water is being injected into this pore- system through a well at constant rate, an oil bank is built up, gas being expelled from the space taken by the oil as shown in Fig. 1. The saturations within each

By Aloys IL. Wollrab

The conditions that govern the selection of a suitable type of detachable bit for the small, isolated mine, for rock work and tunnel contracting and for the large mine are quite dissimilar, therefore intelligent recommendation of a particular make of detachable bit must involve consideration of many factors. Small, isolated mines may find advantageous a detachable bit that a larger mine cannot afford to use, because of more efficient conventional steel sharpening and steel-distribution practice, but a small mine may not be able to adopt the practice of large mines because of necessary capital expenditures for equipment for detachable-bit sharpening and . shanking. The perfect detachable bit, suitable for all conditions, has not yet been developed. Conventional Drill Bit in Use That drilling speed increases as the bit gauge decreases is well known, but since small-hole drilling is the exception rather than the rule the rate of such increase is probably not so generally recognized. Tests carried out by Holman Brothers Limited1 with 7/8-in. steel show that when bit sizes are reduced from I½ in., I3/8 in., and I3/16 in-; to I3/8 in., I1/4 in.., and I1/8 in., respectively, the volume of the hole is I 5 per cent less and the drilling speed 49 per cent higher. Recent tests by the United States Bureau of Mines2,3 in hard, uniform basalt showed that a reduction in average gauge from 2.077 to I,826 in., a difference of o.25I in., gave an increased drilling speed of 65 per cent. The limits to which a drill hole may be extended depend upon the loss in gauge. Since the conventional bit with 5° and 14° clearances did not possess sufficient reaming edge to permit the smaller gauge changes that were required for small-hole drilling, experiments were made in bit construction with a view to correcting this deficiency. This resulted in the adoption of the full reaming cross bit (having full Carr charac1erist.i~~) by some mines4 In order to drill holes having a minimum taper from the collar to the bottom of the hole, full reaming center-hole cross bits with 90° cutting angles, 5° and 14° wing tapers, forged on 7/8-in. quarter-octagon drill rods, are used in the conventional drill-steel practice at Hollinger. In the steel shop close attention is given to the condition of the dies and dollies, which, combined with a rigid inspection of the finished bit, ensures as nearly a perfect bit as call be forged economically. Shop practices and costs have been discussed in earlier paper.5,6 The method by which the radii for the special dies used for forging bits of different gauge diameter are obtained so that the points and reaming edges cut circles of the same diameter has been discussed by Hibbert. Requiremnts for Detachable. Bit for Hollinger Under these it it was appar- ent that it would be difficult to introduce a detachable bit that could successfully compete with the conventional bit already in

Jan 1, 1943

By Aloys IL. Wollrab

The conditions that govern the selection of a suitable type of detachable bit for the small, isolated mine, for rock work and tunnel contracting and for the large mine are quite dissimilar, therefore intelligent recommendation of a particular make of detachable bit must involve consideration of many factors. Small, isolated mines may find advantageous a detachable bit that a larger mine cannot afford to use, because of more efficient conventional steel sharpening and steel-distribution practice, but a small mine may not be able to adopt the practice of large mines because of necessary capital expenditures for equipment for detachable-bit sharpening and . shanking. The perfect detachable bit, suitable for all conditions, has not yet been developed. Conventional Drill Bit in Use That drilling speed increases as the bit gauge decreases is well known, but since small-hole drilling is the exception rather than the rule the rate of such increase is probably not so generally recognized. Tests carried out by Holman Brothers Limited1 with 7/8-in. steel show that when bit sizes are reduced from I½ in., I3/8 in., and I3/16 in-; to I3/8 in., I1/4 in.., and I1/8 in., respectively, the volume of the hole is I 5 per cent less and the drilling speed 49 per cent higher. Recent tests by the United States Bureau of Mines2,3 in hard, uniform basalt showed that a reduction in average gauge from 2.077 to I,826 in., a difference of o.25I in., gave an increased drilling speed of 65 per cent. The limits to which a drill hole may be extended depend upon the loss in gauge. Since the conventional bit with 5° and 14° clearances did not possess sufficient reaming edge to permit the smaller gauge changes that were required for small-hole drilling, experiments were made in bit construction with a view to correcting this deficiency. This resulted in the adoption of the full reaming cross bit (having full Carr charac1erist.i~~) by some mines4 In order to drill holes having a minimum taper from the collar to the bottom of the hole, full reaming center-hole cross bits with 90° cutting angles, 5° and 14° wing tapers, forged on 7/8-in. quarter-octagon drill rods, are used in the conventional drill-steel practice at Hollinger. In the steel shop close attention is given to the condition of the dies and dollies, which, combined with a rigid inspection of the finished bit, ensures as nearly a perfect bit as call be forged economically. Shop practices and costs have been discussed in earlier paper.5,6 The method by which the radii for the special dies used for forging bits of different gauge diameter are obtained so that the points and reaming edges cut circles of the same diameter has been discussed by Hibbert. Requiremnts for Detachable. Bit for Hollinger Under these it it was appar- ent that it would be difficult to introduce a detachable bit that could successfully compete with the conventional bit already in

Jan 1, 1943

By Aloys H. Wohlrab

THE conditions that govern the selection of a suitable type of detachable bit for the small, isolated mine, for rock work and tunnel contracting and for the large mine are quite dissimilar, therefore intelligent recommendation of a particular make of detachable bit must involve consideration of many factors. Small, isolated mines may find advantageous a detachable bit that a larger mine cannot afford to use, because of more efficient conventional steel sharpening and steel-distribution practice, but a small mine may not be able to adopt the practice of large mines because of necessary capital expenditures for equipment for detachable-bit sharpening and shanking. The perfect detachable bit, suitable for all conditions, has not yet been developed. CONVENTIONAL DRILL BIT IN USE That drilling speed increases as the bit gauge decreases is well known, but since small-hole drilling is the exception rather than the rule the rate of such increase is probably not so generally recognized. Tests carried out by Holman Brothers Limited1 with 7/8 -in. steel show that when bit sizes are reduced from I ½ in., I 3/8 in., and I 3/16 in., to I 3/8 in., I ¼ in., and I 1/8 in., respectively, the volume of the hole is 15 per cent less and the drilling speed 49 per cent higher. Recent tests by the United States Bureau of Mines2,3 in hard, uniform basalt showed that a reduction in average gauge from 2.077 to I.826 in., a difference of 0. 2,5I in., gave an increased drilling speed of 65 per cent. The limits to which a drill hole may be extended depend upon the loss in gauge. Since the conventional bit with 5° and I4° clearances did not possess sufficient reaming edge to permit the smaller gauge changes that were required for small-hole drilling, experiments were made in bit construction with a view to correcting this deficiency. This resulted in the adoption of the full reaming cross bit (having full Carr characteristics) by some mines.4 In order to drill holes having a minimum taper from the collar to the bottom of the hole, full reaming center-hole cross bits with 90° cutting angles, 5° and 14° wing tapers, forged on 7/8-in. quarter-octagon drill rods, are used in the conventional drill-steel practice at Hollinger. In the steel shop close attention is given to the condition of the dies and dollies, which, combined with a rigid inspection of the finished bit, ensures as nearly a perfect bit as can be forged economically. Shop practices and costs have been discussed in earlier papers.5.6 The method by which the radii for the special dies used for forging bits of different gauge diameter are obtained so that the points and reaming edges cut circles of the same diameter has been discussed by Hibbert.7 REQUIREMENTS FOR DETACHABLE BIT FOR HOLLINGER Under these circumstances, it was apparent that it would be difficult to introduce a detachable bit that could successfully compete with the conventional bit already in

Jan 1, 1942

By W. E. C. Coxe

At the meeting of the Institute in Philadelphia, in June, 1876, it was my pleasure to read a paper on the "Manufacture and Endurance of Iron Rails." I then spoke of some trial rails which had been placed in the down track of the Philadelphia and Reading Railroad, over which passed, in addition to merchandise and passengers, most of the heavy coal traffic of that company. One of these rails, made at the Philadelphia and Reading Rolling Mill in 1870, and then placed in the track, was removed in 1876, after having carried about 55,000,000 gross tons, and was on exhibition at the Centennial Exhibition. A piece of this worn rail, twisted cold, was also shown there. One of the same series of rails was allowed to remain in the track until 1878, and short sections of this rail, as well as one not worn, to show its original shape, are presented for your inspection. A comparison of the two will show that the top of the head or tread has morn down 3/16ths of an inch during its nine years of service. It carried in that time 67,000,000 gross tons of freight, passengers, cars, and engines. This rail was made in the usual way of manufacturing iron rails at the Philadelphia and Reading Rolling Mill. The head was made from puddled iron bars, piled, heated, and rolled into bars, 41/2 and 3 inches wide by 1 inch thick, these bars, breaking joints, were made into a pile in section 9 inches square, heated and rolled into slabs 9 inches wide and 2 inches thick; the balance of the rail-pile was made of 41/2 and 3-inch bars, rolled from two-thirds old rails and one-third puddled iron, the

Jan 1, 1880

By Becket, Frederick M.

CHROMIUM is but one hundred and thirty years of age-a mere youngster as related to many metals that' have speeded world progress. It was Vauquelin of France who proved conclusively that the so called red lead of. Siberia contained a new element. The variety and characteristic colors of the compounds suggested the name chromium. He also succeeded in reducing oxide of chromium to the metallic form and described the product as very brittle, infusible, needle- like crystals on which acids had very feeble action. His metal was not pure chromium, of course; it must have contained appreciable carbon in the combined form as a result of reducing the oxide by carbon at high temperatures. Vauquelin's description in 1798 of this work is a gem-indeed, literally, he went so far as to discover the presence of chromium oxide in the emerald. The metallic product did not seem to interest Vauquelin greatly, but a new chemical industry began shortly after his discoveries.

Jan 1, 1928

By P. J. Potter

PRACTICALLY all tin-base babbitt metals used in engine bearings are made to customers' specifications, which are many and varied. The copper ranges from 3 to 8 per cent. and the antimony from 4 to 13 per cent.; generally, the babbitt with lower copper content will contain from 4 to 8 per cent. antimony and that with higher copper will have from 7 to 13 per cent. antimony. The allowable lead content varies from 0.20 to 2.00 per cent. If a solder is used as a bonding material instead of tin, the resulting material in the finished bearing will have a higher lead content, but it would not be enough to bring the lead above specificational limits. Impurities such as iron, arsenic and bismuth should be determined in the tin before using to insure a uniform and high-grade product. These points must be considered when segregating and grading the waste that comes from the finishing operations on lined bearings.

Jan 1, 1929

By C. G. Dunn, F. W. Daniels, M. J. Bolton

IN recent papers on interface energies in metals¹,² the concept of an equilibrium of forces has been used in the measurement of interfacial tensions. Mathematically the equilibrium of three forces is given by the relations: where the 2's are the interfacial tensions (interface energies per unit area of interface) of three phases or grains meeting at angles 21 22 and 23 (212 relates to the 1-2 boundary formed by grains 1 and 2;223 to the 2-3 boundary, etc.). If these relationships are valid, one can calculate relative values of the interface energies from measured boundary angles on specimens which have been brought to equilibrium. Since Eq 1 may be derived through a mathematical process of minimizing the grain boundary energy under the restriction that the ?'s be independent of boundary orientation: the concepts of surface tensions and equilibrium of forces are not particularly essential. To deal with the general case involving dependence of boundary energy on boundary orientation, it becomes desirable to drop certain concepts formerly held (namely that energy per unit area is identical with force per unit length or surface tension) and to use the energy concept alone. It is appropriate, therefore, to use E in place of ? in deriving and using the more general equations that express the anisotropic nature of the grain boundary energy. Herring3# ' recently has derived the required general equations using the principle of minimization of energy. Specifying the boundary orientations in terms of angles (4) measured with reference to crystal axes within the grains, Herring's equations take the form E23 + E21 cos?8 + E12 cos?2 — sin ?12 + sin?2-?E12/?12 =O [2] where the partial derivatives are measured in the direction of counterclockwise rotation of the boundaries. Eq 2 implies that an infinitesimal displacement of the triple point along the 2-3 boundary produces no change in the boundary energy. Similar equations apply for infinitesimal displacements along each of the other two boundaries. From such equations Herring obtains the following general relationship (1 + E1 E2) sin?8 + (E2 — E1) cos?3 ________ E38______________ = (1+ E2 E8) sin ?1+ (E3— E2) cos ?1 __________^5____________[3] (1 + E sin ?2, + (E1 — E8,) COS ?2 1 E28 where E1 = 1/E23- E25 and PC and c8 have similar expressions. It is apparent that Eq 3 reduces to Eq 1 when the c's vanish. Eq 3 also reduces to Eq 1 when the E'S are all equal. Shockley and Read' have pointed out one limitation to these equations. When E plotted versus 4 appears as an energy cusp, as their theory requires, for example, for the energy near a twin boundary position, then Eq 3 (and therefore Eq 1 also) no longer applies if one boundary is in the minimum energy position. One of the equations of form Eq 2, however, applies if the infinitesimal displacement is along the boundary associated with the energy cusp. From the foregoing treatment it will be apparent that equilibrium angles alone are not sufficient in general for calculating relative interface energies.

Jan 1, 1951

By James Douglas

THOUGH liberality is not supposed to be a prominent trait of the Scottish character, Canada owes to a Scotchman, Sir Wm. Macdonald, more than to any other of its people, not only wise ideas, but pecuniary help towards extending education: and another Scotchman, in New York, has sumptuously housed under one roof three branches of the engineering fraternity, of which we are one. Having thus created us members of the same family-for the metaphorical meaning of house and kinship is identical-Mr. Carnegie expresses more emphatically than even he could in words, that, by affording facilities for closest intercourse, he in¬vites the mechanical, electrical and mining engineers to par¬ticipate in the freest interchange of idea and experience, and to correlate and combine the results of their studies and activi¬ties; and, being members of the same household, to banish re¬serve and secrecy. And now we, the members of the - American Institute of Mining Engineers, meet as though we were at home in a neighboring country. For whether we meet in Canada, in England, or elsewhere, the Institute is always received as though no political or geographical divisions separated its members from those of congenial associations in the land of its host. In truth, the title which we have assumed claims for the sphere of our activities the whole American continent, regardless of such trifling details as boundary-lines. The fact that we meet to communicate each other's experience, to discuss our difficulties, and to seek each other's aid in solving the intricate problems that so often present themselves in the course of our profes¬sional life, is an acknowledgment of our individual helpless¬ness; and therefore an argument for united effort. But no effort can be of any value if there is an underlying suspicion

Jan 9, 1907

SUCCESSFUL development of a new process for heat hardening of pellets made from taconite concentrates was announced by Arthur G. McKee & CO., steel plant engineering and construction firm of Cleveland, and Allis-Chalmers Mfg. Co. An order for the design, engineering, and materials for a plant incorporating the process, has been received by the McKee Co. from the Reserve Mining Co. for its new E. W. Davis Works at Silver Bay, Minn. It is estimated that this plant will cost around $19 million and when in full operation, will turn out 12,000 tons of pellets per day.

Jan 10, 1954

"The mountains of Utah contain one of the largest deposits of high grade bituminous coal in the world. According to the United States Geological Survey, there are 13,130 square miles of land known to contain workable coal, and these extensive fields contain 196,000,000,000 tons of coal. More remarkable than the extent of the coal fields is the thickness of the coal beds. Over three-fourths of the output of coal in Utah is recovered from beds ranging from 8 to 17 feet in thickness, as compared to one-eighth of the output of the entire country from such beds. In 1917, Utah mined one-third of its coal from seams at least 16 feet thick, compared to one-half of one per cent of the total bituminous output of the country from like seams.Coal at Wales, in Sanpete County, and in the vicinity of Coalville, Utah, was, it is reported, the first discovered by white men in the state. Wales claims the distinction of having produced the first coal mined in Utah. Two men, who had been coal miners in Wales, learned of the coal from an old Indian chief who called it ""rock that would burn."" In 1857, the town of Wales was founded and coal mined, and in 1858 some coke was manufactured and hauled by ox team to Salt Lake City. South of Wales is Castle Valley, in Wasatch Plateau field. From 50 to 60 miles of the Old Spanish Trail from Santa Fe, New Mexico, to Monterey, California, lies in Castle Valley. The coal in this field may or may not have been known at the time the trail was used extensively. The first published reference to this coal, however, was made by a party of the Corps of Topographic Engineers in their journal for October 11, 1853.After the completion of the Union Pacific railroad in 1869, mining on a commercial scale was attempted. In 1876 the Utah and Pleasant Valley railroad commenced operations between Scofield, in Carbon county, and Springville, Utah county, and following the year 1878, when the Rio Grande Western railway began construction through the Carbon county field, development increased until in 1900, when large smelters commenced operations in Salt Lake valley and gave coal mining in Utah an impetus that first carried it to an annual output of a million tons. During the past fifteen years many new mines have been opened, and with the construction of the Utah railway, an exclusive coal road, from the properties of the United States Fuel company in Carbon and Emery counties to connect with the Union Pacific system at Provo, the state reached a maximum production of 6,005, l 99 tons in 1920."

Jan 1, 1925

By A. O. HAYES

SYSTEMATIC methods of ore-finding are looked to the more as increasing production requires greater supplies of raw materials. Unrelenting search for new sources of supply is necessary, and all the skill of science must be displayed both in methods of discovering and recovering the minerals necessary to the demands of present-day life. To this end most national governments have some sort of a geo- logical survey and there is a growing understanding of the desirability for cooperation between federal and state or provincial organizations and also financial assistance, from state and private universities, mining companies, railroads and manufacturers. Such surveys are now being directed by well trained geologists selected from federal, state and university departments. Large-scale maps are being prepared and better geo- logical interpretation made, more thorough chemical and physical examinations are being made and original search is fostered, with the result that successful prospecting is better directed, new mining regions are more likely to be discovered, and the life of. old camps lengthened.

Jan 1, 1931

By W. E. C. Coxe

AT the meeting of the Institute in Philadelphia, in June, 1876, it was my pleasure to read a paper on the "Manufacture and Endurance of Iron Rails." I then spoke of some trial rails which had been placed in the down track of the Philadelphia and Reading Railroad, over which passed, in addition to merchandise and passengers, most of the heavy coal traffic of that company. One of these rails, made at the Philadelphia and Reading Rolling Mill in 1870, and then placed in the track, was removed in 1876, after having carried about 55,000,000 gross tons, and was on exhibition at the Centennial Exhibition. A piece of this worn rail, twisted cold, was also shown there. One of the same series of rails was allowed to remain in the track until 1878, and short sections of this rail, as well as one not worn, to show its original shape, are presented for your inspection. A comparison of the two will show that the top of the head or tread has worn down 3/16 ths of an inch during its nine years of service. It carried in that time 67,000,000 gross tons of freight, passengers, cars, and engines. This rail was made in the usual way of manufacturing iron rails at the Philadelphia and Reading Rolling Mill. The head was made from puddled iron bars, piled, heated, and rolled into bars, 4 1/2 and 3 inches wide by 1 inch thick, these bars, breaking joints, were made into a pile in section 9 inches square, heated and rolled into slabs 9 inches wide and 2 inches thick; the balance of the rail-pile was made of 4 1/2 and 3-inch bars, rolled from two-thirds old rails and one-third puddled iron, the

Jan 1, 1880

By Robert Linton

AT its meeting on May 21, the Board of Directors approved the recommendations submitted by President Lovejoy and named a nominating committee for the year that is especially well distributed as to major technical interest and as to geography. As may be seen from the list published herewith, two come from the East, two from the Midwest, and three from the far West. Mr. Linton, the chairman, has been a valued member of the Institute for 36 years. A memorandum drawn up by Paul D. Merica, representing the A.I.M.E., and W. R. Barclay, representing The Institute of Metals of Great Britain, setting forth a reciprocal plan for special memberships in each Institute for members of the other, was discussed. Both societies already have formally approved the plan in principle and Dr. Merica was clothed with full authority to agree on a few small details that have not been settled, and conclude the arrangement in behalf of the Institute.

Jan 1, 1936

By HENRY M. PARKS

THE total production of all metals in Oregon to date is estimated at $160,000,000; ~115,000,000 from eastern Oregon and $45,000,000 from the western part of the state. In 1916 the metal production of the state was approximately $4,000,000, while the present annual production has dwindled to a little less than $1,000,000. Western Oregon The state of Oregon contains several metal-bearing areas, widely scattered in different regions. More than half of its coast is fringed with a belt of auriferous sands which sometimes are rich in fine gold. A second mining field, the chief producing one of western Oregon, is situated in the southwestern part of the, state and includes Jackson, Josephine, Douglas, Coos and Curry counties. It may be considered as the northern extension of the gold and copper belt of California. A third region in western Oregon is that on the western slope of the great Cascade range in the Bohemia, Blue River, Quartzville, North Santiam and Ogle Creek districts-from the Siskiyous on the south almost to the base of Mt. Hood near the Columbia River on the north.

Jan 1, 1925

Jan 1, 1896

By C. E. MacQuigg

MAN?S desire to harden metal is older than recorded history and obviously would date from the moment when he found his implements were not equal to the demands of service. This need for hardness in metal may be divided roughly into two main classifications: (1 :I need for hardness through- out-for purposes of greater strength or elasticity of the whole implement or member, and (2) need for surface hardness alone. A strong steel needed to transmit stresses or resist de- formation is an example of the first class. In metals only surface- hardened, the chief need is for resistance to wear. Obviously the whole gamut of all uses can be imagined- from the extreme of a simple cantilever supporting a load in space to that of a solidly supported face plate serving to resist wear. It is the in- creasing of wear resistance which I propose to discuss.

Jan 1, 1939