The Iron Age 1910-03-10: Vol 85 Iss 10

THE IRON AGE New York, Thursday, March 10, 1910. COPMIPRESSED AIR AND ITS USES.—II. Horizontal Excavation. In vertical pneumatic excavation, maintaining proper air tension is rather simple. Usually it is kept a little stronger than the hydrostatic pressure at that level. Where unknown pressures of water and quick- sand are likely to be encountered, trouble may be avoided by making test borings. Fig. 7.—A Shield Used by the Hudson Companies. * Horizontal pneumatic excavation is very dif- ferent. It is conducted simultaneously at vari- ous levels, so that there is a range of hydrostatic head. The Pennsylvania tunnel diameter of 23 ft. means a difference in hydrostatic head _ be- tween the top and bot- tom of Io Ib. per square inch, An air tension adjusted to keep the upper surface dry will not keep the bottom dry, and the tension required by the bottom will be in danger of blowing through the top. _ So that, if it is porous or loose, such an escape of air would lower the ten- sion and let water. and mud rush in. In prac- tice, a pressure about midway between the two extremes of hydrostatic head is used. This means an excess pressure on the roof and a deficient one at the bottom. If the over- lying soil is inadequate to retain even this lower pres sure, a blanket of clay is sometimes dropped over the tunnel. This may be a very expensive although neces- sary remedy, It is said that the clay blanket for the East River tunnels of the Pennsylvania Railroad cost about $300,000. The bottom of the tunnel will be wet be- cause of the insufficient pressure, and, if of sand, may be too soft to sup- port the heavy steel shield used in construc- tion, thus permitting de- viations from the grade of the tunnel and break- age of the cast iron lin- ing enveloped by the shield. Broken seg- ments can be easily re- placed, but deviations in grade may be difficult to - correct; the unwieldly shield must be maneu- vered and the tunnel it- self redirected, requir- ing the use of special cast iron lining sections. The direct effects of gravitation play but lit- tle or no part in ver- Fig. 8.—A View of a Shield from the Rear or Tunne! Side. Fig. 9.—A Close View of the Rear of a Shield. tical excavation. The compressed air, assisted by the skin friction, easily supports the great weight ot caisson, air shaft and concrete, and sometimes ad- ditional weight is necessary to secure penetration. Penetration to a material which will permit sud- den and large escape of the compressed air is very improbable, but both of these may and do occur in tun- neling. The solid material in the roof is, no doubt, at times partly supported by the upward pressure of the air, but this is only true to the extent that the material is impenetrable by the air. A porous, thin overlying stratum may be encountered at any time, especially where blasting must be done, an excess of material may be dislodged which will create a cavity at whose top the hydrostatic head is reduced and the protective covering made thinner, and a blowout may occur from either or both of these conditions. In this event, the greater the volume of air to the rear the better, for the pressure will not so soon be lost and with the compressors mean- time at top duty, disaster can be averted until the hole is stopped. Then outside material may settle in an close the hole more permanently. In horizontal penetration through rock and part rock, it is a great prob- lem to blast, excavate and remove the rock so that the different opera- tions do not interfere with each other. The condition where the face of the excavation is rock to a level near the top and where the overlying material needs support upon removal of the rock is one of considerable difficulty. To blast away the rock and still find a means of supporting the roof is the problem. The New York Tunnels, The subaqueous tun- nel work recently com- pleted or nearing com- pletion in and around New York City consti- tutes in the aggregate the greatest example of THE IRON AGE Fig. 10.—A Section of Completed Tunnel Before the Laying of March 10, 1910 horizontal pneumatic excavation. The island of Manhattan is en- tered by only two rail- roads—the New York, New Haven & Hart- ford Railroad and the New York Central lines. The Pennsylvania, the Baltimore & Ohio, the Lackawanna, the New Jersey Central, the Erie and other roads have to transfer their passen- gers by ferry. The tun- nel system of the Penn- sylvania Railroad which will shortly be put in operation extends from a point on the west in New Jersey about a mile back from the Hudson River, passes under that stream, continues un- derground across Man- hattan Island, dips be- low the East River and rises to the surface on the Long Island side. In actual operation are two dis- tinct lines of the subfluvial system of the Hudson Com- panies. These lines connect with the New Jersey side. In operation also is the subaqueous tunnel line which connects the original New York subway with that of 3rooklyn. As far back as 1873 a company was organized to construct a tunnel beneath the Hudson, and from the very first it was the plan to use compressed air. The walls were to be lined with sheet iron rings, each con- sisting of a number of sections of %-in. plate, 2% ft. wide, connected by 3-in. angle bars. Such a ring when assembled and braced formed a kind of retaining wall. A brick lining would then be constructed for the 2% ft., and in much this manner the tunnel progressed. It was at first proposed to construct a double track tunnel, but so much difficulty arose on account of the size of the cross section that it was soon determined to construct a tube for each track. This plan has since been adhered to in all subaqueous work in New York. Following the rather crude method, briefly described, two tubes were pushed out from Fifteenth street, Jer- sey City, toward the New York shore, one for a dis- Track. March 10, 1910 Fig. 11.- tance of 500 ft., and the other 2000 ft. It is said that it was impossible to maintain alignment or grade. Later on construction was continued by a somewhat different method, using a shield. The tunneling shield was invented by Brunell in England about 1818. Subsequent use and experience have somewhat modified it, but the fundamental idea has persisted. Essentially the shield consists of a stout cylindrical shell with a strong partition trans- verse to the axis which may have several openings in it. This structure serves to restrain the surrounding material. A permanent lining of brick or cast iron is constructed from the point of origin to a point well within the shield. If the initial end of this lining is securely supported against a horizontal thrust by ar- ranging jacks to operate from the other end against the shield partition, the shield itself may be given a very powerful thrust forward. Ordinarily, this thrust is not expected to perform actual excavation. The shield is jacked forward to occupy a newly excavated sec- tion ahead. This will usually have been dug or blasted out by workmen in advance of the partition. However, the forward rim is called the cutting edge, and in. some of the tunnel work beneath the Hudson it was possible to secure penetration by the jacks and without em- ploying men at the head of the shield. If the soil is ‘quite soft, the power available suf- ficient and the shield it- self strong _ enough, penetration may be made, thus even with the entire partition closed. In other cases where conditions are not so favorable, a portion of the partition may be left open for the ingress of the mud. The shield then advances, “ bleed- ing” its way. The shield may be operated with or without compressed air. The first tunnel under the Thames, Lon- don, was driven by the use of the shield and without the employment of pneumatic means. This tunnel was com- pleted in 1843. Fig. 12. THE IRON One of the Hudscn Companies’ Systems AGE 555 The Hudson tubes were continued by the use of the shield, an iron plate lining and compressed air. A tube was also started from the New York side to meet the northerly and longer one of those go- ing out from the Jersey City shaft. This last tube had only penetrated about 160 ft, when work was suspended. The Jersey tube which was to meet it had been lengthened until it meas- ured 3916 ft. long. Al- together there was now constructed 4646 ft. of tunnel, 4076 ft. belong- ing to one tube. Upon the resumption of work later on it was on the completion. of this tube that constructional activities centered. The method of the shield was continued. The internal diameter of the iron lining was 18 ft. 2 in. It was expected to use this tube for a double track electric railway, whose rolling stock would necessarily have been on a rather small scale. It was realized, however, when this matter had been fully considered, that this solution of the problem would be inadequate. Accordingly, work was recom- menced on the other tube, of which only 570 ft. had been completed. The internal diameter for this work was determined as 15 ft. 3 in. On the New York side the tunnel work was extended eastward to the junc- tion of Ninth street and Sixth avenue, and thence northerly along the latter. On the New Jersey side the old idea of having a terminal between the Lacka- wanna and Erie depots was abandoned. It was de- cided to run the tunnel construction northward by a semicircular curve to a terminal in Hoboken adjacent to the Lackawanna Station, and also to curve off to the south and thus reach the Erie Station in Jersey City. Further, by constructing a short section, direct connection might be established between the two cities. These plans involved three junction points, one at the the shore where the two curves separated; the others where the short section joined these two curves. of Air Locks. The Caisson for a Junction on the Jersey Shore. 556 Fig. 18.—An Interior View of the Same Caisson Over a Year Later. The first of the subaqueous tubes joining: the two banks was completed in 1904. In 1908 regular trains began to run between Hoboken and the New York station at the junction of Sixth avenue and Nineteenth street. Before this it was decided that two other tubes should be pushed beneath the Hudson connecting a downtown New York terminal at Fulton and Church streets with the Pennsylvania Railroad station in Jer- sey City. By connecting with the tubes to the north in the vicinity of the Erie station the whole system of four subaqueous tubes would be unified and an inde- pendent connection established between Hoboken and the two railroad stations in Jersey City. At present almost this entire system is in operation, plus an ad- ditional station in New York at Sixth avenue and Twenty-third street. Construction along Sixth avenue is to be continued to Forty-second street and thence easterly to the Grand Central Station of the New York Central Railroad. A tunnel has already been constructed from this point easterly beneath the sur- face of Manhattan Island, then under the East River, to connect with the Long Island side. This tunnel is not now in operation. It is also proposed to construct a sub-surface line from the station at Sixth avenue and Ninth street easterly to Fourth avenue. This last point is at the site of the Wanamaker store. There will thus be connections at Forty-second street and at Wanamaker’s with the original New York subway. Somewhat to the north of Hoboken and at a point about opposite Thirty-fourth street, in New York, the Pennsylvania tubes pass beneath the western shore of the Hudson and do not rise to the surface until far. to the east in Long Island. This railroad will not only enter New York, but will pass through it and connect with New England by way of Long Island. Entrance into Long Island is by tube; exit from it and connec- tion with the mainland to the north will be by way of a great steel bridge. All but a small part of the subaqueous tunnel con- struction about New York has been by means of the shield. Details have varied, but the general character of the several shields has been the same. Fig. 7 shows a shield used by the Hudson Companies. Although somewhat of a wreck, the general structure of its bulk- head framework may be distinguished, This shield has penetrated the wall of a caisson constructed on the Jersey side at one of the points of junction referred to before. At the rear may be seen the front edge of the THE IRON AGE March 10, 1910 iron lining. When a shield is jacked forward the length of a section of the lining, one ring will pass out of the shield at the rear. It drops down an amount equal at least to the thickness of the Shield shell. The roof of the excavation, if the ma- terial is soft, will settle down at once upon the top of the lining. This is a defect attaching to this method of construc- tion, since it is desirable to cover the outside sur- face of the iron lining with Portland cement grout. It seems that no practical method is known by which this premature settlement of the roof can be averted. Fig. 8 is a view of a shield from the rear. The face of the excava- tion may be seen through openings in the bulk- head or diaphragm. By close inspection a num- ber of the jacks. may be discerned; three are in view in the lower left-hand quadrant. It has been found better to disconnect the apparatus employed in the erection of the lining from the shield. While the shield in Fig. 8 is in normal position, that in Fig. 7 shows that rotation has occurred, which it is scarcely practicable to avoid. It is permitted until it begins to interfere with operations, when the shield is righted by special efforts. In Fig. 8 dead rollers may be seen arranged at mid- elevation on each side. Upon these the platform carry- Copyright by Scribner’s Magazine. Fig. 14.—A View.of the System of Caissons for the Connections of the Hudson Companies’ Tunnels on the New Jersey Side. March 10, 1910 ing the erecting apparatus is moved forward. The erector consists essentially of a ram or plunger which may be moved back and forth in a radial direction. By suitable devices this plunger and its case may be rotated. In this way every point in the circuit of a ring of lining may be commanded. The outer end of the plunger may be seen in Fig. 8 near the head of the man on the right. A typical ring consists of nine segments of cast iron, all of about the same length, and one short segment used to effect closure. Near the center of gravity of an ordinary section a special lug is cast, to which the outer end of the erector plunger is temporarily bolted while lifting and placing the seg- ment. Each segment is flanged on all four edges and drilled to be bolted to adjoining rings and sections. Each ordinary segment has 18 bolt holes, and the key eight. Thus, 85 bolts are required for each ring. These are 1%4-in., with rolled threads. The contacting surfaces of the flanges of the segments are finished to yield a tight joint. In Fig. 8 may be seen a turntable, evidently used to prevent the lining from spreading. The shield pro- pelling jacks are hydraulic, with a stroke of 2% ft., or 6 in. more than the length of a ring, thus providing am- ple clearance. The 16 of them each had a plunger diameter of 8 in., and at 2% tons per square inch each jack was capable of exerting a pressure of about 125 tons. The shield could, accordingly, be pressed ahead with a pressure of about 2000 tons. To allow such pressures the shield itself had to be very substantial. Upon at least one occasion the shield was driven through the silt at the rate of 1 yd. per hour for 24 hours. This is at the rate of 0.4 in. per minute. Fig. 9 is a close view of the rear end of a shield, clearly showing the jacks. Apparently this shield is still in the shaft and has not started actual service. Fig. 10 is a view of a portion of the tunnel system of the Hudson Companies after completion of the tube itself, but before laying of track. The length of tube actually under air pressure may be considerable, which is an advantage, as already ex- plained, but wherever the bulkhead is situated it is subjected to a total pressure that is proportional to the area of its face. In work carried on by the Hudson Companies a tension as high as 48 lb. per square inch was employed for a short time; if this was borne by a single bulkhead 18 ft. in diameter, the total amounted to nearly goo tons. Fig. 11 is a view of one of the Hudson Companies’ systems of air locks. The locks are shown in a bulk- head securely intrenched in the solid rock. The main lock has its door open. Although but a single track passes through it, the exterior arrangement of tracks permits its use both for incoming and outgoing cars. This lock is for the passage of men and the bulk of the freight. Another lock above is an emergency cham- ber and is purposely located high, so that if the tube is flooded it will be serviceable longer than it would otherwise. Of the two tubes which were first constructed be- tween New Jersey and New York, the north one car- ries the outbound track from New York and the south one the inbound track. On the Jersey side both tracks connect, with branches off to the north and to the south. To avoid crossings the outbound junction is superimposed upon the inbound one. The necessary thinning of the walls of earth between the tunnels in the vicinity of the points of junction and the actual junctions themselves necessitated special constructional provisions. A concrete and steel caisson ror ft. long and 51 ft. deep was sunk to provide suitable chambers to receive the tube ends. There were two decks or stories, the upper for the outbound junction and the lower for the inbound one. This caisson was wider back from the shore to permit the divergence of the tracks. As water was to be encountered, this large structure was sunk by pneumatic methods. Fig. 12 THE IRON AGE 557 shows this caisson. The wider or western end is in the distance. In the foreground, an air lock, together with its operating platform, is in plain view. The twisted rods of the reinforcement are everywhere in evidence. At each side is a track permitting cranes to be moved along the length of the caisson. One ofthe movable cranes is apparently serving the caisson through the air lock in front. Fig. 13 is an interior view of the same caisson about 14 months later, taken in the lower chamber, looking west. To the right is the tube carrying the inbound track from Hoboken. On the left is the inbound tube from the south (Jer- sey City). By close examination, the bolt holes of the end of the lining may be discerned. A bulkhead has been put in place, closing the opening. But access to the tube may be obtained through the air lock seen at the bottom. Reference has already been made to a short section joining the north and south curves and so enab- ling direct connections to be made between Hoboken and Jersey City. Two other caissons were sunk where the necessary junctions were made. The one to the north was very similar in form and dimensions to the one already described. Its narrow end was toward Ho- boken. The southern caisson was rectangular in plan, 106% ft. long and 45 ft. wide, and had a depth of 44 ft. Each of these caissons had two stories. As their upper stories on the side next New York received the outbound tubes from the first caisson, and their lower stories received the inbound tubes, it will be seen that the two upper stories were not in agreement as to the direction of train movement and that the same was true as to the lower stories. This would have been a mat- ter of no moment, perhaps, if it had not been for the short section making direct connection between Hobo- ken and Jersey City. To harmonize the disagreement, the two tubes constituting the short section were planned to twist slightly about each other and thus per- mit the joining of the lower story of one caisson with the upper story of the other. In consequence of the arrangement of the tracks described, no tube or its con- nections is operated in more than one direction. The southerly caisson not only received four tubes at its northern end, but four tubes pass from it at its south- ern end. The upper and lower tubes at the south end next the river after a passage southward, curve in again and recross the Hudson by the two tubes connecting with the extreme downtown district of New York. The remaining tubes from the south end are to connect with Jersey City and Newark. The shield shown in Fig. 6 is entering this rectangular caisson from the south. This view represents conditions in December, 1908. A portion of the general scheme of the Hudson Compa- nies has not yet been developed. But already all four subfluvial tubes are in service. Fig. 14 is a view of the system of caissons and the corresponding tubes look- ing toward the north, with the Hudson River to the right. With the account already given, this drawing should be readily understood. ‘ (To be continued.) ————+VD--oe_—__ The Abendroth & Root Mfg. Company, Newburgh, N. Y., calls attention to the fact that installations of spiral riveted pipe 30 years ago must have been of pipe manufactured by that company, as it was then the only maker of such a product. This statement appears to have been rendered necessary by the appearance of publications by other and more recent manufacturers, who have referred to the satisfactory service rendered by such pipe, and probably have inadvertently omitted to mention that the installations made so long ago were by the pioneer company. The first heat was taken at the new open hearth steel plant of the Maryland Steel Company, Sparrows Point, Md., March 2. There are five 50-ton tilting fur- naces, and steel will be made by the straight open hearth or by the duplex process. re rag ne eg eerie eee en eter pe ee en ee Pre Se Fae SE RR a RT 558 The American Institute of Mining Engineers, The Pittsburgh Meeting. The ninety-eighth meeting of the American Insti- tute of Mining Engineers was opened on Tuesday, March I, at the Carnegie Lecture Hall, Pittsburgh, with rather a small attendance, although the proportion of older members who had gathered was conspicuously large. Owing to the unavoidable absence of Julian Kennedy, who was to deliver an address of welcome, Dr. John A. Brashear, the well known scientist, spoke of Pittsburgh’s ambition, so rapidly being realized, to become a center of learning, education and the fine arts. After due acknowledgment by D. W. Brunton of Denver, president of the Institute, Dr. R. W. Raymond read a biographical notice of the late Dr. Charles B. Dudley of Altoona, whose splendid professional attain- ments and lovable personal qualities had endeared him to all. H. P. Bope of the Carnegie Steel Company, in an admirable address, reviewed the career and pro- nounced a discriminating eulogy of the late William Metcalf of Pittsburgh, a past president of the Institute and a leader and a pioneer in the manufacture of high grade crucible steels. Prof. Robert H. Richards of the Massachusetts In- stitute of Technology, Boston, presented a paper on the “ Development of Hindered Settling Apparatus,” tracing the steps, in the study of classifiers for con- centrating ores, which have led to development of the apparatus, of which he is the inventor. Professor Richards, who is our foremost authority on ore con- centration, has obtained truly wonderful results witi machines which are remarkable for their simplicity and which depend for their operation upon “ hindered set- tling” or upon the “teetering” of particles of mate- rial in currents of water. While chiefly applied thus far to lead and copper ores, the apparatus is likely to obtain more extended application, in the dressing of iron ores, which is being more widely introduced in this country. The session was closed with a lecture illustrated by a series of lantern slides, by S. C. Beyl, on mining in Argentina. Wednesday Morning's Session was opened by F. Z. Schellenberg of Pittsburgh, who read a paper entitled “ The Systematic Exploitation of the Pittsburgh Coal Seam.” He sketched briefly the characteristics of that famous seam and classified the methods pursued in mining in the gas coal and coking coal districts, the width of rooms and ribs, and the withdrawing and advancing systems as affected by the necessity of keeping control of the roofs. He dis- cussed the effect of considerations imposed by ventila- tion, by the desire to secure tonnage at an early date, and noted the influence, upon layout, of the introduc- tion of machine mining. Mr. Schellenberg stated that under favorable conditions as high as go per cent. of the area of the Pittsburgh seam is extracted. An asso- ciate of Mr. Schellenberg explained in detail the meth- ed pursued in extracting the ribs, in retreating, in the coal district. W. H. Blauvelt of Syracuse, N. Y., in a paper en- titled “‘ A Commercial Fuel Briquette Plant,” described the works of the Solvay Process Company and the Semet-Solvay Company, at Detroit, Mich., which em- ploys a mixture of coke breeze and dry noncoking coal from either the Hocking Valley or the Jackson Hill districts, with coal tar pitch as a binder. Mr. Blauvelt’s paper is particularly valuable for the reason that it goes far beyond a mere description of the individual plant in giving details of cost and in discussing the causes of the failure of so many briquetting enterprises to attain commercial success. He dwelt, too, upon the future of the briquetting industry in attaining a smoke- THE IRON AGE March 10, 1910 less fuel for domestic purposes in competition with anthracite. The paper was discussed by C. T. Malcolm- son of Chicago, a specialist in coal briquetting, who referred particularly to the results obtained at the plant of the Standard Fuel Company of Kansas City. E. W. Parker of Washington noted that balls of coal had been made as early as 1600 and announced that the coal statistics for 1909 indicate that that year had shown a very marked development in the production of the briquetting industry. George S. Rice, who has charge of the United States Geological Survey Testing Station at Pittsburgh, summarized the contents of his paper on “ Dust Ex- plosions in Coal Mines,” which takes up particularly the question of the temperature and humidity of mine air in its effect upon the explosibility of coal dust. A very interesting contribution to the subject was presented by C. M. Young of Lawrence, Kan., in a paper entitled “ The Gaseous Decomposition Products of Black Pow- der.” Mr. Young has studied experimentally the gases of the explosion of black powder with a view to deter- mining whether and to what extend they themselves are explosive, and as such may contribute to or originate mine explosions. He finds that on an average they yield about 50 per cent. of carbonic acid, 6 to Io per cent. of carbonic oxide, 1 per cent. of methane and 35 to 40 per cent. of nitrogen. He draws the conclusion that, in the presence of dust coal and of gases distilled from coal, the products of combustion of black pow- der are combustible, besides stirring up coal dust dan- gerously. Mr. Young dwelt also upon the marked tendency among miners to use larger quantities of powder, until they have become coal shooters rather than coal miners. In Kansas the average tonnage of coal obtained from a 25-lb. keg of powder has declined to 16 tons. He holds that one of the principal causes of the greater frequency of coal mine explosions in recent years is the enormously increased quantity of powder used. The session closed with a brief paper by J. A. Holmes of the United States Geological Survey on the work of the technological branch at Pittsburgh. This was largely explanatory of the plant and the work of the United States Geological Survey Testing Station at the Arsenal at Pittsburgh, which the members vis- ited in the afternoon, and where they witnessed a series of highly interesting tests. Wednesday Evening’s Session, In the evening Dr. David T. Day of Washington spoke on the “Accumulation of Petroleum in the Earth.” It was not his purpose to discuss the genesis of petroleum, but to account for some of the striking variations in the character of oils of individual fields and of the similarities of oils of distant fields. Dr. Day holds that the shales act in very much the same way as does fuller’s earth in the laboratory in the frac- tionization af oils, and submitted the results of nu- merous experiments in that direction. Professor Wadsworth of the School of Mines of the University of Pittsburgh spoke on the somewhat radi- cal ideas which have been adopted in the principles underlying the objects of that institution. Professor Crabtree outlined the aims of the educational work of the four departments of the Carnegie Institute, which is now teaching 2000 pupils. The tuition is exception- ally low, and, contrary to the opinion generally pre- vailing, its endowment is only partly adequate to meet the requirements of the broad field which it aims to cover. E. Gybbon Spilsbury of New York brought forward a “ New Method of Cyaniding Gold and Silver Ores.” It consists in using a new product known as “ silica- sponge,” which is being manufactured at Syracuse, N. Y., by the Just Process Company of 45 Broadway, New York, and which possesses extraordinary proper- ties. Mr. Spilsbury submitted a series of results ob- tained in different cyaniding mills in this country and March 10, 1910 THE in Mexico, which show that the yield of the precious metals has been very greatly increased, with a notable saving in time. Mr. Spilsbury has also developed what he calls a catalytic tile, which holds out unusual promise of better results in the manufacture of sulphuric acid. Silica spong has also attractive probabilities as a filter- ing material. Arthur Dwight of New York presented a paper on further results obtained with his method of blast roast- ing for lead and copper ores, which has been introduced in a number of large plants. Friday’s Session, The last session, on Friday, was crowded with papers. It is worthy of note that in number, variety and scope, the professional contributions to the Ameri- can Institute of Mining Engineers have shown a marked development. It is in the attendance at meet- ings that the Institute shows such a striking contrast to the gatherings of other technical societies. Dr. Robert Bell of the Canadian Geological Sur- vey, Ottawa, Canada, in the course of a summary of his paper, “ The Huronian as a Gold Bearing Ter- rane,” dwelt upon the effect of the glaciation upon the Huronian areas of eastern Canada, and expressed the opinion that many gold mines will be developed. He pronounced the Klondyke gold to have been derived from the Huronian, in which it was widely distributed. Enormous thicknesses of the rocks, possibly up to 2 miles, have been disintegrated in place, the gold being concentrated in the narrow V-shaped channels. In the Klondyke there was no glaciation which removed the decayed rock and its gold contents. Walter O. Snelling of Pittsburgh, a facile and log- ical speaker, presented an interesting paper on “ The Action of Explosives on Rocks of Different Degrees of Hardness.” He explained the principles which should guide in the selection of explosives, in mining, under varying conditions. Iron and steel makers will read with deep interest the paper by George W. Maynard of New York on “The Introduction of the Basic Steel Process in the United States.” Mr. Maynard, who was the represen- tative in this country of Thomas and Gilchrist, has . added to his records of the introduction of the basic process the evidence of those who were. identified with the work at different plants. In a paper by David B. Rushmore of Schenectady on “Electric Mine Hoists,” an elaborate analysis was presented of the electrical and mechanical require- ments of hoisting, diagrams being shown relating to the ordinary reel, the conical drum, the combined cyl- inder and conical drum, and the Whiting drum. Mr. Brunton, president of the Institute, referred in the dis- cussion to the admirable work being done at a mine in Idaho with an electric hoist. E. F. Burchard ofgthe Geological Survey spoke on “ The Investigations of Structural Materials for Use in Federal Buildings,” the materials referred to being granites, marbles, concretes, sand, limes, &c. Mr. Burchard showed a map of the country, indicating the location of the 350 buildings on which the United States Government was engaged in 1908, these public buildings involving an outlay of $50,000,000. The survey is co-operating with the office of the supervis- ing architect in studying the sources of building ma- terials, often of local interest only, and their quality. This study is not alone of very great importance to the government as a builder, but to the country at large. J. L. W. Birkinbine of the Birkinbine Engineering Offices, Philadelphia, outlined the contents of his paper on “Coal and Iron Ore in Western Oaxaca, Mexico.” Mr. Birkinbine has spent several years in the explora- tion of a district in the state of Oaxaca, which, while it was supposed to contain coal and iron, had been visited by very few engineers. He has studied the IRON AGE 559 field from a geological and economic point of view and has made topographic surveys, the general result . of which has been the location of a promising field of what is very close to anthracite coal and a district capable of producing bituminous coal of fair quality. Iron ores have been located in quantity, being mag- netites and limonites, high in quality, both as to per- centage of metal and low contents of sulphur aiid phos- phorus. Surveys show, too, that, despite th®*moun- tainous character of the region, it can be tapped by a railroad with a maximum grade of 2 per cent. During the sessions there was shown for the first time a portrait by Farley, a Philadelphia artist, of the late Thomas M. Drown, who for many years was sec- retary of the institute. The portrait, which is an ex- cellent likeness of Dr. Drown in the days of his active connection with the Institute, was presented to the so- ciety by James Gayley, Dr. James Douglas and Dr. R. W. Raymond. ———————»—--o———__—_—_ Hydroelectric Power Development in Russia. The March Proceedings of the American Institute of Electrical Engineers says: As a result of the development and successful op- eration of high tension transmission lines in the United States, interest in electrical engineering progress in this country is rapidly growing in Russia. This has been stimulated by the recent investigations of Prof. H. J. Ryan and Ralph D. Mershon. The Ministry of Ways and Communication at St. Petersburg has be- come interested in a scheme of hydroelectric power transmission which will involve the electrification of suburban divisions of the state railroads, and the sub- ject is now under consideration. As some doubt seemed to exist in the minds of some of the officials as to the reliability of a 100,000-volt transmission line as compared with a 60,000-volt line, the latter being the highest in use in Europe, telegraphic inquiries have been made of some of the leading men in the electrical engineering profession in America as to the comparative merits and reliability of the two lines. Prof. M. A. de Chatelain of St. Petersburg, an asso- ciate of the American Institute of Electrical Engineers, and one of the most enthusiastic exponents of hydro- electric development in Russia, has been invited to make a demonstration of some high tension transmis- sion experiments with new types of insulators and different sizes of conductors before the officials in- terested. The advance of electrical engineering in Russia is likely to open a new and extensive field to American engineers. coer Ga recess The Ford Chain Block Company.—F. J. Ford and Clement Restein have formed a partnership, under the name of the Ford Chain Block Company, 133 North Second street, Philadelphia, Pa., to engage in the manu- facture of chain blocks. One of their specialties is the Triblock spur gear chain lock, in which are used cut steel gears, drop forged steel hooks, steel crossheads and driving pinions and the best quality of tested and hand- welded chain. This selection of materials makes pos- sible a block that is most compact and of great strength. All parts are interchangeable and the workmanship and care exercised in the construction are claimed to con- duce to easy working and long life. At the Alabama City, Ala., plant of the Southern Iron & Steel Company the first heat of 50 tons was taken March 2 at the open hearth department after the recent rebuilding and overhauling. There are six furnaces, the four originally built and two, on which construction was begun a few years ago, recently com- pleted. It is expected that the rod mill at Alabama City will start up April 1 unless weather conditions are unfavorable. 560 The Thomas Basic Process.* History of Its Introduction Into the United States. BY GEO. W. MAYNARD, NEW YORK. At the Pittsburgh meeting of the American Insti- tute of Mining Engineers in May, 1879, I made the first announcement in America of the results obtained by Sidney Gilchrist Thomas and Percy C. Gilchrist in their efforts to eliminate phosphorus in the manufac- ture of steel in the Bessemer converter and the open hearth. The first published statement in an American news- paper appeared in The Jron Age in 1879 and was a re- print of the first Thomas-Gilchrist paper which I sent to James C. Bayles, at that time the editor. At the suggestion of many of my friends who were present at the Pittsburgh meeting and others who are cognizant of the beginnings of the process in this country, and for the information of the younger generation of the iron and steel fraternity, I have thought it eminently proper that the history of the process in detail should be given where I made the first announcement and where the process has had its largest development. During my residence in England from April, 1873, to February, 1879, and membership in the Iron and Steel Institute since 1874, I was present at many of the meetings of that institute during those years. At nearly every meeting the burden of discussion was the question of the employment of pig iron containing phosphorus in the manufacture of steel by the Bessemer and open hearth processes. Years of Investigation by Thomas, In my biographical notice of Thomas, read at the New York meeting of the American Institute of Min- ing Engineers, February, 1885, I show that the work- ing out of the process was not a haphazard or acci- dental inspiration, but, on the other hand, the culmina- tion of many years of investigation of the experiments and theories which had been carried on and advanced by chemists and metallurgists at home and abroad. The foundation of Thomas’s great achievement was his chemical knowledge, having passed an examination in inorganic chemistry “first class advanced” at the School of Mines in Jermyn street, as the outcome of attending night lectures and working in a little labor- artory at his cottage in Battersea, where it was my good fortune to spend many evenings with him. He supplemented his chemical work by visits to English, Belgian and German iron and steel works when he could get away for short periods from his exacting duties in the Thames police court. The First Announcement Before the Iron and Steel Institute, At the March meeting of the Iron and Steel Insti- tue in London in 1878, at which I was present, I. Low- thian Bell read a paper on “ The Separation of Phos- phorus from Pig Iron.” In the discussion which fol- lowed George J. Snelus stated that six years before he “took out a patent for using lime for the lining of steel melting and other furnaces ”—a patent which was still valid and that he had then casually told a good many members of the institute that he had succeeded in re- ducing phosphorus in Cleveland pig iron to less than 0.I per cent. by using limestone as the lining of his furnace. There were, however, practical difficulties in applying the lime both in the Bessemer converter and in the Siemens rotary furnace, and he had been beat- ing his brains about for several years in order to over- come them. Among those who took part in the discussion was a young man, a visitor, who stated that he had suc- of Mining Engineers, March, 1910. cI Eie anden THE IRON * Read at the Pittsburgh meeting of the American Institute AGE March 10, 1910 ceeded in effecting the almost complete removal of phosphorus in the Bessemer process. Experiments had been carried out at Blaenavon, with the co-opera- tion of E. P. Martin, on quantities varying from 6 Ib. to 10 cwt., and some hundred analyses made by Mr. Gilchrist (who had the conduct of the experiment from the first) showing the removal in the converter of from 20 to 99.9 per cent. of phosphorus. He believed the practical difficulties in the way had been overcome and that Cleveland pig iron might be made into good steel without any intermediate process; he hoped on a future occasion to lay full details before the institute. The young man was Sydney Gilchrist Thomas. J. S. Jeans, who was present and subsequently be- came the secretary of the institute, in his work on “ The Creators of the Age of Steel,” says: “ The meet- ing did not laugh at the youthful Eureka, nor did it congratulate the young man on his achievement, much less did it inquire about his methods of elimination. It simply took no notice of his undemonstrative announce- ment.” A. L. Holley Calls Attention to the Process, On Saturday, September 14, 1878, A. L. Holley and I had planned to leave London to attend the Paris meeting of the Iron and Steel Institute. As we were about starting for the Charing Cross station I was summoned to the North of England on some engineer- ing work. We parted with the expectation of meeting in Paris within a day or two. My work prevented my going. Within a week I received a letter from Mr. Holley inclosing a paper which had been submitted to the Council of the institute for presentation at the Paris meeting. The title of the paper was “On the Elimination of Phosphorus in the Bessemer Converter by Sidney G. Thomas, F.C.S., and Percy C. Gilchrist, Associate Royal School of Mines, F.C.S.” Mr. Hol- ley in his accompanying letter said: “ This looks alt right, and if upon examination you find it to be so you had better get control of the process for the United States.” The simplicity of the chemistry of the process and the vast possibilities immediately appealed to me, so without delay I telegraphed to Mr. Thomas through Mr. Deby, the foreign secretary of the institute, to call on me on his return to London with the view of taking up the process for the United States. , To quote from R. W. Burnie’s memoir of S. G. Thomas: “ The paper was not read at the Paris meet- ing, although it had originally been placed near the top of the list, but belief in the alleged discovery of an un- known youth had not much spread since March, and the paper was removed to the end, and then left by the authorities unread for ‘lack of time.’” The Process Introduced by Bolckow, Vaughan & Co, Windsor Richards, the manager of Bolckow, Vaughan & Co.’s works at Middlesbrough, was at the Paris meeting. In his presidential address to the Cleve- land Institution of Engineers he said: Messrs. Thomas & Gilchrist prepared a paper giving very fully the results of their experiments, with analyses. In was intended to be read at the Paris meeting in 1878, but so little importance was attached to it, and so little was it believed in, that the paper was scarcely noticed, and it was left unread. Mr. Thomas first drew my partic- ular attention to the subject at Creusot, and we had a meeting a few days later at Paris, when I resolved to take the matter up, provided I received the consent of my direc- tors. That consent was given, and on October 2, 1878, ac- companied by Mr. Stead of Middlesbrough I went with Mr. Thomas to Blaenavon. On arriving there Mr. Gilchrist and Mr. Martin showed us three casts in a miniature cupola, and I saw enough to convince me that iron could be de- phosphorized at a high temperature. I also visited the Dowlais Works, where Mr. Menelaus informed me that the experiments in the large converters had failed owing to the lining being washed out. The outcome of Mr. Richards’ investigation was the erection of a pair of 30-cwt. converters at the Eston Works of Bolckow, Vaughan & Co., at Middlesbrough. March 10, 1910 At the beginning they wrere confronted with the diffi- culty of making basic brick for the converters. Their difficulties were finally overcome, so that on April 4, 1879, they were able to show the iron manufacturers of Middlesbrough “ an absolutely successful operation.” Mr. Maynard Meets Mr, Thomas, On Mr. Thomas’ return to London in September, 1878, he called on me at my request with a view to a personal investigation of the process and its adoption in the United States. At that time I was consulting engineer for the Standard Iron & Steel Company, a Manchester corporation, with works at Gorton, a sub- urb of Manchester. As a substitute for a two-converter Bessemer plant the company had been induced to adopt a process which was to produce steel from any grade of pig. The prac- tical demonstration promptly resulted in the abandon- ment of the process, leaving, however, a “ receiver,” an oblong ganister-lined box with tuyeres on both sides, somewhat on the lines of the Clapp-Griffiths plant. I suggested to Mr. Thomas that a test of his process be made in this receiver, which he thought would be quite feasible and much less costly than the lining of a Bessemer converter. On consultation with the Standard Company’s di- rectors they authorized me to go ‘ahead and voted the necessary funds for carrying on the investigation. In order to make the test as severe as possible I concluded to make the demonstration at Middlesbrough. The Test at the Acklam Works, The proprietors of the Acklam Works very kindly permitted me to set up the receiver at the lower end of the pig bed, the blast pressure of 2% to 3% Ib. being furnished by the blast furnace blowing engine. Messrs. Thomas and Gilchrist and Mr. Stead, the eminent chemist of Middlesbrough, were present, besides some of the officials of the Acklam Works. The basic brick (dolomite) were burnt in an ordinary brick kiln, and, as it transpired, at too low a temperature. The first heat was made December 18, 1878, and the second on the 20th. In both cases the charge was 5 tons of No. 3 iron, containing 1.63 per cent. of phosphorus. In the first charge the resultant metal contained 0.45 phosphorus and no silicon, and the cinder 7.05 phosphoric acid with 31 silica. In the second charge, with the same grade of iron, the product con- tained 0.28 phosphorus and a trace of silicon: The samples were taken by Mr. Stead, who also made the analyses. The product was a bad looking mess, as much of the basic lining floated out of the box along with the steel. I believe these blows were the first after the South Wales experiments. They were shortly followed by the erection of the plant at Eston, and to Windsor Richards is due the credit of having made the first commercial success and for the facilities which he afforded English and foreign steel manufacturers for studying the process. The following analyses show results of the early experiments as carried out at Bolckow, Vaughan & Co.’s Eston Works by Mr. Rich- ards, confirming triumphantly Mr. Thomas’ theory and predictions: 7-——— Metal after blowing for — 14% 16 min. min. 35 sec. Original 6 12 end of 16% endof pig. min. min. blow. min. blow. COSOOR sav ceae 3.57 3.40 0.88 0.07 trace trace ess awe s008 1.70 0.28 0.01 trace nil nil Phosphorus .... 1.57 1.63 1.42 1.22 0.14 0.08 Manganese ..... 0.71 0.56 0.27 0.12 0.10 trace ee 0.06 0.06 0.05 0.05 0.05 0.05 The Acklam experience confirmed me in my wish to take up the process for America. Then followed almost daily conferences with Mr. Thomas on patent and working details up to the time of leaving for New York in March, 1879. In the manufacture of basic brick, or furnace lin- ings, the serious drawback was the slacking of the lime when water was used. This difficulty was overcome by THE IRON AGE "6 561 the knowledge and ingenuity of Edward Riley, the eminent metallurgical chemist, by substituting gas-tar or petroleum for the purpose of making the hard burnt dolomite plastic before molding. I was with Mr. Riley during many of his experiments. Patents were finally granted him on November 25, 1878. I was appointed by Mr. Thomas agent for the United States for the granting of licenses or sale of the patents and for the securing of patents which had not yet gone to issue. Subsequently I was empowered by Mr. Riley to act for him. Horace W, Lash First to Test the Basic Process in an Open Hearth Furnace, It is extremely gratifying to inform you that one of our members, Horace W. Lash, formerly of Pitts- burgh and now of Cleveland, was the first man to test the basic process in an open hearth furnace. Mr. Lash has kindly furnished me with a statement of his work in Belgium in the following letter: I met Mr. Thomas at the autumn meeting of the Iron and Steel Institute, which was held in Paris in October, 1878. Up to this time Mr. Thomas had done but little, if anything, with his lining in the open hearth furnace, his experiments being confined largely to the Bessemer con- verter in the old plant at Dowlais, South Wales. I ad- vised Mr. Thomas that in my opinion the Ponsard Furnace, with which he had been making a number of experiments at Thy-le-Chateau, Belgium, would be a good furnace in which to try out his process, as it would be possible to line the bottom or revolving part of the furnace with his lining, allowing the roof and ports to remain the usual construction of silica brick. In t