The Iron Age 1891-01-01: Vol 47

—_- ‘CHE THURSDAY, JANUARY 1, 1891. IRON AGE The Speed of War Ships. In point of speed, the fastest cruising ship of war in the navy is the San Fran- cisco. The San Franciso, owing to the size of her machinery and heavier fittings, is perhaps able to maintain high speed for a longer period than can any of the new cruisers. Next in point of speed comes the Philadelphia, then in order the Balti- more, Newark, Charleston, Yorktown, Atlanta, Boston, Chicago, Dolphin and Petrel. The dynamite cruiser Vesuvius and torpedo boat Cushing, not being properly cruising ships, do not enter into the above comparison. The Cushing and Vesuvius are the fastest craft in the navy. The main interest, however, centers in the big cruisers of the San Franciso and Philadelphia type. All of the vessels of this class are 19-knot ships, with a possible a source of pride, withal, to the Navy | heat contained in the coal. In large plants Department, and especially to the Bureau | of many horse-power the saving would be of Steam Engineering, inasmuch as her designs are more properly those of Com- modore Melville than are the m: ichinery designs of any other cruiser in the navy. $$ The Otto Gas Engine and Producer Gas. The gradual restriction in the supply of natural gas and the general tendency toward gaseous fuel even in sections where the natural product stimulated a demand for all kinds of gas generators, but owing to the acknowledged | economy and the continuity of the proc- ess, the apparatus making the ordinary so- called producer gas is likely to be the most commonly used where gas of low heating value can be used to “adv antage. OTTO GAS ENGINE OF 120 HORSE-POW speed for one hour’s duration of over 20 knots. The average speed of the four latest cruisers for a mean of a four hours’ continuous run is: San Francisco, 19.75! knots; Philadelphia, 19.678 knots; Balti- more, 19.57 knots, and Newark, 19.54 knots. The San Francisco made 20.06 knots during one hour of the four hours’ run. The Baltimore made 20.2 knots during one bour of her four hours’ ordeal. All of the above vessels are fitted with twin screws, operated by triple-expansion engines. They are all approximately 5000- ton ships. Of the four ships, the fastest, the San Francisco, was built by the Union Iron Works of San Francisco. The femain- ing three were built by William Cramp & Sons of Philadelphis. A fifth cruiser, the Charleston, one of the first ships of the new | navy, and a vessel fitted with compound engines, developed a maximum speed of 18.25 knots and an average speed of | 17.75 knots. It would seem ‘that so long as engine and boiler space continues to be | cut down in the newcruisers the San Fran- | cisco, by virtue of her heavy machinery, Different designs of producers, each hav- ing their own characteristic advantages, are on the market already and used largely for pottery furnaces, burning of bone- black in sugar refineries, &c., as well as in the various iron and steel industries. A striking feature of economy with pro- ducer gas is the absence of chimneys, through which so much heat energy is lost, when, for instance, solid fuel is used under boilers for making steam; and in conjunction with gas engines this advan- tage of gas producers results in the most economical results in the production of heat for power purposes. The high effi- ciency of the gas engine contributes, of course, its share to the general result of the combined apparatus, but it is claimed that the best construction of steam boilers and boiler settings combined with triple ex- pansion engines cannot equal the fuel con- sumption that has been recorded in several instances for large sized gas engines in conjunction with gas producers. With the growth of gaseous fuel the use of gas direct in engine cylinders, made as will continue to head the navy list in| it is needed in producers, ‘the same as steam int of speed. The Western built ship is unquestionably the most” powerful steaming ship in the navy to-day. is made in boilers, cannot fail to become more general. It seems the most rational She is! method for utilizing to the full extent the F | largest, and especially where power is con- sumed day and night, though the method is applic able with good commercial re- isults to power plants of from 20 to 50 | horse-power, owing to the waste of steam power in plants of this size being generally much larger than in that of large engines, the coal consumption reaching often as high as 6 to 12 pounds per horse-power per hour. The gas engine in conjunction with producer gas commonly consumes not is not found have} more than 14 pounds, and sometimes as low as 1} pounds, ofcoal per hour. We presume that some of our readers are not entirely conversant with the details of the process referred to, and we therefore give on the next page a section of the appara- tus as now. constructed and in use at the Otto Gas Engine Works, Philadelphia. 7 MN) ER The gas is made in the producer on a continuous process by air and steam being passed through incandescent coal. From the generator it is taken to the scrubber for the purpose of cleaning and cooling, and is thence allowed to enter a small holder. From thisthe gas engine draws its supply, and in case the production of gas exceeds the consumption, the holder, filling and moving to its uppe r position, will strike a stop, by which the supply of steam and air is cut off from the producer, and the making of gas suspended until the drop of the holder causes it to be re- sumed. The commercial results obtained by the combination of a gas producer with a gas engine have caused a marked increase in the size of the latter now offered by engine builders compared with those formerly constructed. The Otto Gas Engine Works now build engines of 120 horse-power, and several of these now under way iu their shops are intended for use with producer gas. These engines are the largest that have ever been built here or abroad, and our accompanying engraving of one of them will give a general idea of their de- sign. They are arranged with two cylin- ders, one on top of the othcr, so as to wie LE LE NE TOE ne ELIOT TORII WHT eS . . . ss ; = a 2 make use of one crank shaft, to which the power is brought by connecting rods | closely linked together below the crank | pin. Theigniting is done either by in- | candescent tube or by the electric spark, | and all functions of admitting the charge of gas and air, opening exhaust valves, | «&c., depend on the gear shaft which runs parallel with the axis of the cylinder. The space occupied by the engine is about 16 feet in length and 6 feet 9 inches in width, and the usual speed is 160 revolu- tions. The gas consumption varies with the load on the engine, being regulated in an automatic manner by the governor and | ranging in proportion from 1 to 8 between | running idle and running under full load. The shipping weight of this size engine approximates 25,000 pounds. gas | ———EEEE _ ¥ The Nicaragua ship canal builders now | have at Greytown ready for work a large amount of supplies, tools and ma- | chinery, consisting of steam boilers, rock | drills, hoisting engines, railway appliances of all kinds, &c., also nearly all the mate- rials for a first-class machine shop. The projectors have unabated confidence in the ! ferior. oe rt { SIME, PRODUCER success of the work commercially no less than in an engineering point of view. The existing traffic across the Isthmus and around Cape Horn has increased, even without the canal, from 2,671,886 tons in 1879 to 4,507,044 tons in 1887. The same rate of increase until 1895, the earliest date which the canal can be opened, it is calculated, would make an annual traffic of 7,616,904 tons tributary to the canal, enough to net nearly 10 per cent. on a $120,000,000 investment. These are the figures of the canal company. Ten thou- sand miles will be saved by the canal in the trip from New York to San Francisco by?’ water. The recent letter of Acting-Secretary Nettleton, of the Treasury Department, regarding rebates as an element of duti- able value, is a distinct triumph for Hay- den Edwards, our Consul-General at Ber- jin. Mr. Edwards has been trying for more than a year to have the principle asserted which is set forth in the letter of General Nettleton. The principle is that rebates allowed by the German Govern- ment on the raw materiais entering into exported goods shall be estimated as a| a | : ae Ly = Ge LLL hed Lal ob GAS PLANT AT THE | other sizes that THE IRON AGE. words, Mr. Edwards has refused to de- duct the amount of the rebates from the market value of the goods when the in- voices were presented to him for certifica- tion, but has insisted that the goods | should be appraised at their full value in the home market. a Drawing Crucible Steel Wire. BY P. CLAPP, FORNIA WIRE G. SUPERINTENDENT MILL, SAN FRANCISCO, CALI- CAL. The treatment in drawing crucible steel wire to suit the requirements of the Pecific Coast cable roads is soimperfectly under- stood that a few remarks on this subject will no doubt be interesting to some of your numerous readers, The best grades of English crucible steel stand a uniform tensile strain of 200,000 pounds to the square inch, while American drawn wire will stand about 185,000 pounds. Firms in this country have imported the same grade of rods used by English makers, and still the wire produced is much in The secret lies in the treatment of SVTSSTtiatare” ese ts Tr | fh OTTO GAS the rods and wire in its various stages. English makers have a secret process of tempering which is only partially known in this country. Crucible, as well as other grades of steel rods, can only be reduced to a certain ex- tent before the torsional qualities are par- tially or wholly destroyed. The tensile strength is increased and the twisting properties are decreased in proportion in all cases. Annealing steel wire destroys the tensile strength, which can only be brought back again at the expense of the torsional qualities required, unless the wire is tempered by lead and oil, or by some other process. From careful inves tigation there is no doubt that crucible steel rods suitable for tempering in lead, oil, water, or by any other suitable means, can be brought to a point where the| greatest possible requirements are attained. This can be done by running the wire through hot lead and an oil bath kept at a known temperature, and reeling it at a certain speed. A perfect knowledge of the sizes of wire to be treated to produce will stand all tests re- quired must be acquired. There is no known process of drawing part of the dutiable value of the goods | crucible steel wire by slow or quick run- upon entry in this country. In other | ning blocks, or by light or heavy drafts, ENGINE January 1, 1891 that will produce wire from the rods as it comes from the rolis to stand the tensile and torsional tests required for cable road wire. Every reduction in size, by draw- ing, increases the tensile strength and re- duces the twisting qualities. When wire | with less tensile strength and more torsional qualities than required is reduced to a cer- tain size the two required elements will be | brought together. To get the best possible results, the rod must be drawn to a certain size, then treated by some means that will give it the required consistency to draw |}down to the size required, and this can only be done by thoroughly understand- ing the process of treating at the proper |size, and then drawing to a certain other size, then testing to ascertain if require- EB are correct. | If No. 14 is wanted, the proper size of wire to start with must be known and treated, then drawn to size. If upon testing at No. 13 the wire is found to have the proper qualities, another reduction will not do, as this will reduce the necessary torsions; the only remedy is to take a size smaller wire to start with or make it a trifle softer. If the wire is found at No. 14 with too little tensile strength and more resistance to torsion than necessary, then the wire will have to be reduced still further to bring it to the most favorable point. After clean- ing with muriatic acid, the wire may be drawn perfectly even ended by exposing it to the atmosphere and sprinkling a weak solution of muriatic acid and water over it from time to time until a nice dark brown water coat is deposited upon the wire, care being taken not to have the solution too strong. Too much acid makes the wire brittle and reduces the tensile strength as well. Since it is very close in the grain, baking and washing will not wash out and ee A Y “ify Ve Aff yy Ve WORKS, evaporate the acid, as in the case of other grades of soft steel and iron. Wire that does not stand the required tests when | taken direct from the blocks often comes ‘up to the standard by being exposed to the air two or three weeks. Perfectly dry hard soap must be applied to the wire | while drawing, otherwise the wire scrapes ‘and ruins the die plate. en — | The New York Biscuit Company have arranged for the erection of the largest | buildings in the city on Tenth avenue, /near Sixteenth street. The buildings will |be erected on four sides of a hollow |square, which will be 206} by 427 feet in 'dimensions. The factory will contain |40 patent revolving ovens of enormous vapacity, and will employ in the various | branches of the business nearly 10,000 imen. Inthe center of the block will be an engine room containing enormous Worthington and Corliss engines and a | most perfect electric plant for lighting the factory. Outside of the engine room will be a furnace and boiler room containing the largest bank of steam boilers in the United States, and surmounted by a smoke stack 125 feet in hight. The cost, exclu- sive of ground, is estimated at $2,000,000. January 1, 1891 THE IRON AGE. 3 Brick Machine. |appearance. The machine is thoroughly | emneeat 'self contained; it does all the work and This machine is especially designed to | no side machinery is necessary. The main work stiff clay as 1t comes from the bank. | dimensions are: Driving pulley, 60 inches The clay may be delivered bya carrier| diameter, 124 inch face; shaft, 5 inches discharging it into a very heavy cast iron | diameter; bevel pinion, 12 inches in cylinder surrounding the vertical shaft | diameter on the pitch line, and made of which carries the arms that pug the clay | cast iron with machine dressed teeth; the and also gives motion to all other work-| crown wheel is made with hard maple ing parts. The pugging cylinder is differ- | teeth and is 72 inches in diameter. The ential in diameter, the larger diameter | machine weighs 23,000 pounds, and re- beingbeneath where the final pugging is ' quires from 20 to 25 horse-power to drive it. W. Burke, president Tredegar Company, Jacksonville; M. C. Wilson, professor natural science, Normal School, Florence ; Col. Horace Harding, U. 8S. Engineer, Tuskaloosa; treasurer, Henry McCalley, Alabama Geological Survey, University, Aiabama; secretary, Wm. B. Phillips, professor chemistry and metallurgy, Uni- versity, Alabama. The annual dues are $5. The society will meet three or four times a year at different places in the State. for the reading and discussion of papers, THE GRANT LEVIATHAN BRICK MACHINE. done and the clay delivered to the molds. | It is made by the Straub Machinery Com- The machine is practically double, having | pany of Cincinnati, Ohno. upon each side a mold, a pressing plunger | and a discharging plunger. While the} brick is being pressed on one side afin-| The Alabama Industrial and Scientific ished brick is being discharged upon the | Society was organized at the University of other, giving two complete bricks at each | Alabama, on Thursday, December 11, revolution. Thus, at the moderate speed | 1890, with 70-members. The objects of of 17 revolutions per minute the product | the society are the promotion of the in- per hour would be 2040 bricks, which | dustries of the State and the furtherance are claimed to beso perfect and so dense | of scientific investigation of the problems that no pallets are required, but the brick | that arise in civil and mining engineering, can be trucked directly to the hacks or| geology, smelting, and the manufacture of dryer. ;coke. The officers for the year 1891 are : The brick is pressed on edge and de-| President, C. Cadle, general manager livered to the off bearing belts directly | Cohaba Coal Mining Company, Blockton; beneath the molds. The brick leaves the | vice-presidents, Thomas Seddon, president press with smooth, flat sides, square edges | Sloss Iron and Steel Company, Birming and corners, and requires no trimming, |ham, C. P. Williamson, president Wil the result being that the Brick will lay | liamson Iron'Company, Birmingham; W. close and present asmooth and finished ' E. Robertson, city engineer, Avniston; J. EE _ which willafterward be published for the use of the members. The next meeting will be held in Birmingham, January 28, 1891. Eugene H. Cowles of the Cowles Elec- tric Smelting and Aluminum Company, Cleveland, Ohio, writes a letter to the New York 7'ribune in which he criticises both the terms ‘** aluminium ” and ‘*‘ aluminum” as being too long for utility, and suggests as a name for the new metal the word ‘* alium,” The Municipal Assembly of St. Louis, Mo., has begun a warfare against the smoke nuisance in that city. A bill is shortly tocome up before them requiring every manufacturer to use a smoke con- sumer, and making it a misdemeanor to fail to comply with same. ew re ee IY a _ a’ 2 =e THE IRON AGE. January 1, 1891 The Creusot Armor-Clad Fort. | vaults, and that there are arrangements | ment must be either expressed or implied, for hoisting it into the firing chamber. A and consent by implication must be so Some years since the Belgian Govern- | greater part of the weight of the gun is|clear and unmistakable as to leave no ment decided to adopt for the defense of the Meuse and Escaut rivers armored forts on the general plan of General Brilamont. Contracts for the construction of these forts were divided among a number of French works, ten of them being given to the Creusot works of Schneider & Co. The latter firm completed its first some time since, and in October made its first trials with it in the presence of numerous | interested officers. Le Génie Civil has published an article on the subject by E. Weyl, from which we take the following: The forts are arranged so that nothing is exposed above the level of the ground but the dome of the cupola, which is ar- mored with 200 mm. steel armor. The conditions to be met were to provide guns with hydraulic brake and automatic re- covery, the recoil being limited to one caliber. The design was to allow of a cus ea =) \ MY SS range between 25° elevation and 2° de- pression for the guns. The accompany- ing engravings show clearly the general arrangements of the fort. It will be ob- served that it consists of a dome of armor abutting against a chilled iron ring 320 mm, thick at its upper edge and 240 mm. thick at its lower part. The armored dome is separated by a plate iron cylin- der reinforced by 14 riveted columns. The platform is borne upon a ring and rollers so that it can readily rotate, spe- cial arrangements being made to provide against a movement of the dome as the re- sult of the firing. Twofold provision is made for aiming the gun, the first being to rapidly revolve the chamber so as to bring the gun to bear approximately, and the other located in the firing chamber for the exact aiming. The armor of the dome is divided trans- versely into three plates, the joints being made with lead. The chilled iron ring is formed of six segments bolted together. The two guns themselves are projected beyond the two firing holes when occasion demands it. It will be observed that the ammunition is stored below in masonry | counterbalanced, as shown in the draw- |ings. The experiments carried on at the | Creusot works with the completed fort | |showed that there was little annoyance | from the firing of the guns in the chamber and very little trouble from the smoke. It | is interesting to add the results | firing tests made on a section of the armor intended for the forts. The engravings | given show the effects of the projectiles | both on the front and on the back of the | plate. Five shots were fired at the cor- |ners and at the centers of a 250 mm. |square, the projectile being a 39 kg. | chilled iron Chatillon-Commentry. The shots themselves are numbered on the plate. No. 1 penetrated 147 mm., the | | | projectile remaining intact and falling in | 'front of the plate. The same was true | also of the other shots, the second pene- | trating 148 mm., the third 149 mm., the} = N SS NN ~ : » \ THE CREUSOT ARMOR-CLAD FORT. fourth 144 mm., and the fifth 150 mm. The plate itself did not show the trace of a crack, which proved it to be homo- geneous. Le Making Contracts by Correspondence.* That which is known in law asa con- tract is, in practical effect, the foundation of all business transactions. A large pro- portion of business contracts are entered into as a result of negotiations conducted by correspondence; and there are many special principles of law which govern the making of contracts in this manner. The essential elements of a contract are con- sideration and agreement. Without a sufficient and valid consideration a con- tract cannot be enforced, and without the mutual agreement of the parties no con- tract can be created. Each of the parties concerned in a contract must agree to all the items of the contract which any of the others agree to, and if there is a single item to which one of the parties does not agree, there is no contract. This agree- * Copyrighted, 1890, Law News Bureau. of the| ad | ground for question as to the intent of | the party against whom the consent by implication is urged. The inception of a | contract made by mail is in the posting of a letter containing a proposition. A prop- osition made in this way is absolutely binding upon the proposer, if it is | accepted before it is recalled. It may, | however, be recalled or countermanded up to the time it is accepted. If it is desired to withdraw a proposition made by mail, the withdrawal must be brought into the actual possession of the party to whom the proposition is made before it 1s accepted. To illustrate: Let us suppose that a mer- chant in New York desires to submit to a merchant in Chicago a proposition for the sale of goods. He deposits in the mail a letter containing his proposition, and by the next mail forwards a letter withdraw- ing or modifying the offer made in his AN \\ WN \ AX \\ MY \ UXO KK first. If after the receipt of the propo- sition, and before the receipt of its with- drawal or modification, the merchant in Chicago deposits in the post office an ac- ceptance of the proposition, the contract is complete and the withdrawal is of no avail. If the letter of acceptance had been signed and sealed, but at the time of receiving the withdrawal should still be in the possession of the Chicago merchant, the withdrawal would be operative and the contract would not be consummated by the acceptance. The theory of the law is, that in the one case the acceptance is still within the control of the acceptor, while in the other it has passed beyond his control. It is undoubtedly a fact in practical ex- perience that if the acceptance were still in the possession of the post office at Chicago it would be subject to recall, but the law fixes upon the time at which the letter is actually placed in the possession of the post office as the time at which the rights of the parties are determined. In order to constitute a contract the accept- ance must be an absolute and uncondi- tional acquiescence in all the terms of the January 1, 1891 THE IRON AGE, vo proposition. If the acceptance is coupled { goods might be shipped to him. On the with conditions they must, in turn, be un- | same day this was written the other party conditionally accepted, and so on, until at | wrote a letter containing additional prop- last there is an absolute acceptance by | ositions. These additional propositions | each party of all the propositions of the} were considered by the first party, and other. This acceptance need not always | negotiations were continued for some time, be expressed in words, but may sometimes | and finally dropped. Afterward the pur- be implied from the acts of the acceptor. | chaser endeavored to assert a contract of | If, after the submission of a proposition, | agency for five years, because the goods were the one to whom the proposition is sub- | shipped after the receipt of his letter, out- mitted proceeds as if it had been accepted, lined above. But the fact that negotiations that will amount to an acceptance of the | were continued after the shipment of the DETAILS OF THE CREUSOT ARMOR-CLAD proposition, provided the acts were such| goods showed that the parties had not as would be entirely inconsistent with a| arrived at a final agreement and that no denial of acceptance. But the acts relied | contract had actually been entered into. |commodity of fixed value. upon to show an implied assent to a| written proposition, and so constitute a contract by implication, must be such acts as are absolutely inconsistent with any other theory than that of the acceptance of the proposition. would accept the agency for certain goods, concerning which negotiations were pend- ing, and requested that a contract be made for five years, and directéd that ‘‘ under these conditions ” a certain quantity of the A person wrote to | another that under specified conditions he | Where the terms of a contract are nego- tiated by correspondence, a condition of | limitation which is once proposed and accepted need not be thereafter repeated or referred to in order to preserve its force, if it was definitely agreed upon. An offer made by letter may be }accepted within and is binding for a reasonable time after its receipt by the one to whom it is made. What is a reasonable time depends entirely upon the circumstances. An offer made on an active market could not be held for con- sideration as long as an offer made on a As a general rule the acceptance of an offer before the intervention of any circumstances which affect its value is within a reasonable time, though this is a matter governed almost entirely by the established usages of trade. What would be a reasonable time in one case would not be a reasonable time in many other cases; an acceptance | within a week might be sufficient in some L texte FORT. cases, while a delay of a day might be fatal in others. Inthis, as in most com- mercial matters, the law is largely deter- mined by the evidence of good faith. Where a contract has been made by mail it may be proved by the correspondence between the parties. The one desiring to prove the contract may introduce the letters of the other party in evidence, and serve upon him a demand that his own be produced. If this demand is not com- plied with he may then prove their con- tents by letter press copies or other mem- oranda made at the time, using them for the purpose of refreshing the memory of 2S : r eS ee be ») 4B » D. Ve. y 6 THE IRON AGE. the witness who gives the testimony. The man may be used as direct in his favor, except as outlined above. formation of contracts by correspondence Wedding’s work deals almost exclu- letter press copying book of a business | sively with the basic Bessemer process, evidence | and for that reason is only of minor direct against him, but it cannot be as evidence | interest to American iron masters. It is /still an open question whether the basic 7 . . i These few suggestions regarding the Bessemer process will be able to compete | successfully against the acid Bessemer on Nod ala ode mA nM 1) may contain much that is familiar to many business men, but if the cases which are litigated in the courts may be taken as an indicator they lead to the conclusion that | many men constantly engaged in making contracts are not entirely familiar with the practical application of the funda- mental principles of contract law. NEW PUBLICATIONS. W EDDING’S Basic BESSEMER PROCESS. Translated by William B. ceeds ro o., and Ernst Prochaska. Published by Scien- tific Publishing Company, New York. $3.50. Dr. Hermann Wedding is so well known a metallurgical writer that no discussion of the merits of his work need be gone into. The original work was an addition to Wedding’s ‘‘ Metallurgy,” originally un- dertaken as a translation of Percy’s classic | work, but gradually developed into a far more valuable text book. The work, which was published in 1884, contains the best connected account of the basic Bessemer process, although probably « better book might be compiled from the data published in the leading technical journals. This, apparently, the translators felt unwilling to dc. Weare particularly pleased, how- ever, that they take special pains to attract attention to the work done in the early stages of the basic process by von Ehren- werth. His studies constitute the most striking example in modern metallurgy of the results obtainable by purely theoreti- cal deduction. While practical steel work- ers were groping their way to the de- termination of the best specification for basic Bessemer pig, he showed by com- putation that phosphorus could be em- ployed in the place of silicon as the heat producing element. It has alwaysseemed as though he was not accorded the credit to which he is unquestionably entitled. foo My ah) (it { NH ry W a ay Nd January 1, 1891 |of iron plants having almost entirely de- |veloped the latter. The translators of | Wedding’s work seemed to have realized | that fact, and Ernst Prochaska has added | a chapter, in which, however, he fails to draw as sharply as it should be done the line between the pig and ore process, as typified by the Brymbo practice, and the pig and scrap, which is the method in more general use. The translators have under- taken occasionally to annotate, but have hardly gone far enough. Thus they fail to call attention to the fact that the Kauff washing process is being practiced on a large scale at two works in this country. #’The translation, on the whole, is good, although it might well have been made less literal without any danger of conveying properly the author’s meaning. Such lapses as calling a neutral lining an ‘‘ in- different” lining should not occur, how- ever, ne Two important ordinances have been signed by the Mayor of Philadelphia, which have an intimate bearing upon the future prosperity of that city. One author- izes the construction of the Belt Line Railroad, comprising a cordon of tracks on the river front, which is expected to give an incalculable relief to the shipping and general mercantile interests of the port. The Reading Terminal bill pro- vides for elevated tracks on some of the main streets and for extensions into the suburbs. The United States immigration returns for 11 months of this year show an in- crease of 20,826 from Bohemia, Hungary |and Austria over last year, an increase of |more than 50 per cent. The Denmark, | France and Germany returns are about as ‘last year. The United Kingdom shows a merit us COUPHES BELGES rata” hy Ain AD NS { in ct th ¥ anon de OL AnD ae) re Effect of Shots on Front of Plate. SECTION OF the one hand and the open acid or basic on the other in this country. Since the date of Wedding’s book the basic Bessemer relative of the position and the basic open-hearth has changed wonderfully in Germany, the construction hearth ARMOR FOR CREUSOT ARMOR-CLAD FORTS. falling off of 16,634. Italy and Poland increase from 32,120 to 77,899. Brazil is just now making extraordinary efforts to attract European immigration, and the United States can now afford to make large concessions for her benefit. January 1, 1891 THE IRON AGE. ~ ‘ THE EFFICIENCY OF POWER SCREWS. BY ARTHUR J. FRITH, C. E. Considered as an element of mechanism, | the screw is used either for the transmission | of motion or for the compounding and ap.- | plication of power. When it is used as a! | the diameter of the screw and with the|on co -eflicient of friction, and inversely as the number of threads ; while the efficiency of this element 1 E =iy3nby | varies inversely as the number of threads, as the diameter of the screw and as the VALUES OF COEFFICIENT WHICH MULTIPLIED BY W = wo 4% 3aP. nw. DIAMETER OF SCREWS IN INCHES. 6 Fig. 1. transmitter of motion, a governing point in the design is the question of accuracy and wear—but not that of efficiency. | When as in presses, or as in the old| fashioned differential screw jacks, the) screw appears as a compounder of force, | we are all aware that there is frequently a very large waste of energy, and we| must balance against the low efficiency | of this element its advantages asa simple | compact compounder of effort, with the ability 1n itself of holding its load. It will therefore be of interest to de- signers to see how a purely theoretical investigation, founded on practical data, | indicates to us, how enormous is sometimes | this waste of energy, and afew general de- | ductions will show us where and how it can be frequently largely mitigated. If P = the force applied at the spanner, | a = the diameter of the circle described by P, w = the load to be overcome, n = the number of single threads to the inch on the screw, b = the mean diameter of the thread, ft = the co-efficient of friction, d =the mean diameter of the thrust collar, I= the inclination of the thread — Bnb And EH = the efficiency of the screw, then the frictionless expression for the power of the screw, may be expressed as the work of the spanner 3aP= We nm and if the friction of the thread only, be added to the expression, it will become W1+ 3xndf) n in which the energy to be ‘exerted in- c reases directly as the load applied, with 8aP= co-efficient of friction, and not as the load ; or it may be expressed as when it appears that it depends solely on the inclination of the thread and the co- the spauner during one revolution will be Z3aP= Wii + Bn f(b a @y ) o ¢ = ; Mt and the efficiency 1 d = — Beg B= Ll+3nf(h+d) OF T+ ( V7 or the efficiency of the screw is greater as the number of threads, the co-efficient of friction and the diameter of the screw thrust are less—a result evidently correct, or, we may say, the greater the inclination of the thread and the less the diameter of the collar compared to that of the screw, the greater will be the efficiency. The application of these formule will, it is believed, give results that will ap- proximate very closely to those of actual practice. In special cases, however, either or both the diameter of the screw and the number of threads are limited by the practical consideration of commercial sizes and our shop tools. Therefore it will be instructive to show graphically the com- parative energy that would be required or the relative efficiency that might be ex- pected from commercial sizes of screws with whole numbers of threads to the inch. These are expressed in a couple of charts prepared some time since, in which the energy absorbed by the collar thrust and that required by the screw is shown separately. In the chart of efficiency the friction of the thread is alone considered. The abscissas in the firscchar: give for each size of screw and number of threads | the value of that co-efficient, which, multi- | plied by W, the load, will give the calcu- lated energy expended in one revolution of the spanner, to which is added the abscissa of the thrust line, which give similar co-eflficients for various mean diameters of thrust collars. It will be noticed that the lines of in- | crease for the various pitch of screws are par- | allel—and, for instance, that the energy re- | quired to operate a screw with three threads to the inch is but Jittle more than that of | the six threaded screw, while the useful work is double; when acollar thrust of the same size is used the difference is still more |markedly in favor of the coarser thread. Again, with a 6-inch collar and a 6-inch screw, the co-efficients for six threads and a EFFICIENCY OF SCREW WITHOUT THE THRUST 100 * 9 80 70 ou eo FT) 40 3u 2 10% 0% DIAMETER OF SCREWS Fig. 2. efficient of friction. A result similar to that demonstrated practically by Mr. Lewis in his experiments on Worm Gear- ing. (‘‘ Transactions” Am. Soc. Mechan- ical Engineers, Vol. VII.) As the energy absorbed by the thrust is |\3d WJ, if both the friction of the thread | and that of the collar thrust be considered in our expression, then the work expended one thread to the inch are respectively 1.8 + 2 = 3.8 and 1.8 + 2.7 = 4.5, anincrease of about 18 per cent., but the amount of work accomplished is six times greater: If, however, it were desirable to use a 3-inch screw with a 1-inch pitch, the total co- efficient would be 2.6 instead of 3.8, and we would be doing six times the amount of work with two-thirds of the power. SERRE ER ee em eee = - 7 o - See (%, —, Pom ro i we: y= be mal ~ ” ~ In Chart 2 are represented the curves of efficiency for these screws, the friction of the screw alone being considered, which shows how much more efficient is the coarser{than the fine threaded screw, but | Fig. 2.—End Elevation. Fig. and Ram Fig. 3. —Sectional Plan at Step. THE KENNEDY more particularly the superiority of the} smaller sizes. These charts are made out for a value of the co-efficient of friction = ;, which 1.—Side AND THE IRON AGE. ments made by Mr. Lewis for W. Sellers | & Co., is probably close to the ordinary | condition of practice when good lubrica- tion is provided for. Ball or roller bear- | ings are often used for screw thrusts with with in Section, Elevation Cylinder Fig. 4.—End Elevation of Top of Cylinder. FORTER CRANE, a great reduction of the amount of lost | _energy—especially if they be such that have ample surfaces of contact. has appeared in a_ recent There number of according to the large series of experi-!the Mechanical World, a foreign period January 1, 1891 ical, an illustration of a screw in which a large series of balls are introduced between the thread and the nut, with a by-passage to allow the ball emerging at one end to re-enter at the other, an ar- rangement which would undoubtedly reduce the friction to very low limits if the practical difficulties are successfully overcome. To recapitulate, we see that in the use of power screws it is preferable : 1. That they be of small diameter, 2. That the thread of the screw coarse. 3. That sufficient bearing surface on the thread be obtained by lengthening the nut as the diameter is reduced. 4. That if collar thrusts be used they be as small as possible. 5. And an increased number used to ob- tain bearing surface. 6. The step or button thrust is more efticient. be 7 Especially with friction plates to ob- tain surface. 8. That ample luorication should be used to keep down the co-efficient of fric- tion, 9. That ball or roller thrust bearing are the most efficient thrust, when used within proper pressures and where they can be easily cared for. 10. That they had better be of large diameter to obtain bearing surface. i ee a The Kennedy and Forter Crane. The crane of which we here present | drawings of the principal features is the |invention of Julian Kennedy and Samuel Forter of Pittsburgh. Two of them are now in successful operation at the Latrobe Steel Works, Latrobe, Pa. In the drawings B represents the up- right hollow ram or plunger of the crane, which is set at its lower end on a step, C, having a water passage, D, which com- municates with the passage through the ram. E is an inverted cylinder which is fitted on the ram and is vertically movable thereon, being provided with suitable packing F, making a water tight joint be- tween the ram and cylinder. The mast of the crane is composed of upright beams G, secured to the cylinder and provided at the lower end with a foot, H, which en- | circles the plunger and is rotatory on the step C. The top journal I of the mast fits in a suitable bearing or steadiment, whichis notshown. The jib of the crane is compound, being constituted for two parts, one a horizontal part which rests on the vertically movable cylinder and is carried thereby, and the other a pivoted swinging beam which is connected with the hori- zontal part before mentioned and serves to support the same. The swinging beam | may itself be properly called a jib, but in order to prevent confusion of terms we shall designate it as a walking beam, and shall call the horizontal part the jib. The jib J is composed of parallel hori- zontal beams set on top of the cylinder E January 1, 1891 on each side of a vertically projecting por- tion K, Fig. 4, thereof, and held in place by a cap plate, L, so as to be capable of slight longitudinal motion, The walking beam M is composed of parallel beams pivotally connected at an intermediate point N to diagonal struts O and P, which extend from the botttom and top portions of the crane mast respectively. At the outer end the parts of the walking beam M are pivotally connected by a cross bolt, Q, to brackets R, projecting from the beams of the jib, and the inner ends of the parts of the walking beam are provided with chains or flexible connections §, which extend therefrom around sheaves T (journaled in brackets V projecting from the mast) to the cylinder to which they o>>> 3533330905 The Kennedy and Forter Crane.—Fig. 5.— Elevation, Showing Modified Construction of Crane. are fixed. The consequence of this con- struction is that as the cylinder is raised to lift the jib, the draft of the cylinder on the chains § will pull down the inner end of the walking beam M, and will elevate the outer end, as shown by dotted lines in Fig. 1. The burden carried by the jib is supported by the connection of the walking beam to the brackets R, and the load is transferred from the intermediate pivot N of said beam to the diagonal struts O and P, and by them to the mast, on which they exert a vertically com- pressing force. On inspection of the drawing it will be seen that the walking beam performs this function of a lifting support in every po- sition of the jib, and as it is’ composed of separated beams it affords no obstruction THE IRON AGE. to the vertical rise of the jib between them nor to the motion of the trolley on the jib. The consequence of this con- struction is that the great bending mo- ment exerted by the jib on the cylinder or plunger in former cranes is obviated, and the strain is distributed upon the mast in such manner as to secure the most effect- ive results in strength of material and ease of motion of the parts. In cranes where the jib is lifted solely by the direct action of the upright cylin- der the bending moment on the jib being transferred to the cylinder and ram causes these parts to bind, and the resulting fric- tion increases considerably the power re- quired to lift the burden. This is not so in this crane, since the bending moment is taken up by the walking beam and does not appreciably affect the cylinder and ram, which operate without ‘such excessive friction. The advantages of the inven- tion in this regard will be appreciated by the skilled engiveer. Instead of using a stationary ram and a} vertically movable cylinder for operating the crane jib, the parts may be reversed so that the cylinder shall be stationary and that the ram shall move within the same and shall lift the jib. Either construction may be applied to this crane. In the modification illustrated in Fig. 5, the jib J is supported at an intermediate point, not by a walking beam; but the chain or flexible connection S extends from the cylinder and sheaves T over a sheave, V, on the mast, and thence over a sheave, W, at the junction of the struts O and P to the bracket R, or other suitable place of attachment on the jib. Then, as the cylinder of the crane is lifted, it pulls on the chain S, and the force thereby sup- plied will be exerted as a lifting force on the jib at the place of attachment R. This lifting force is transmitted to the mast through the struts in the manner above explained, with reference to the construc tion illustrated in Fig. 1. — i Mower Patents in Dispute.—In the United States Circuit Court in Pittsburgh, the Eureka Mower Company of Utica, N. Y., entered suit against the administrators of E. T. Fox of Towanda, Pa., and the Eureka Mower Company, also of Towanda, for $100,000. It is claimed by the plain- tiffs that in 1883 they purchased from the Towanda Company, of which Fox was president, the patent rights for the ex clusive manufacture of the Eureka mower. Upon the representation of Fox and the defendant company that the rights were exclusive and the profits $12,000 a year the plaintiffs paid $50,000 for the patent rights. Since then, however, they have learned that the defendants did not own | iron which we wish to reproduce. 9 the exclusive rights, and that there are prior patents. They state, also, that they have lost money, and they ask for $100,000 damages. oe The Caleulation of Blast Furnace Charges. BY FRANK F. AMSDEN, B.S., E.M., SCRANTON, PA, Since the production of any desired pig iron is closely associated with its accom- | panying slag, we must obtain an analysis of aslag made at the same time as the pig From this analysis we must calculate the ratio of the SiO, to bases. Having this ratio (say, 0.85 in this case), we can readily calculate the amount of flux to be added to any ‘‘ore mixture” to produce a slag with a composition approximately the same as the one wanted. I make out tables for the limestone, fuel ash and each of the ores as follows: Limestone (100 pounds). Molecular Analysis. weight. SiO, = 3.85 + 6» 4 0.257 Pek : ¢ 215 + 12 x 6=0.12% CaO 28.95 + 56x «=« (2 1.034 MgO = 20.02 -~+ @ X 2=1001 2.161 Excess of basic quantivalence = 1.904 The 3.85 pounds SiO, divided by 0.60 (the molecular weight of SiO,) gives the number of molecules of SiO,. Multiply- ing this quotient by 4 (the quantivalence of SiO.)—we have the total quantivalence of the SiO... The quantivalence of the Al,Os, CaO, &c., is obtained in a similar manner: Fuel Ash (100 pounds). Ash 8.5 per cent. Molecular Equiva- Analysis. weight lence. SiO, 50.00 + 60 b = 3 3333 AlgOs | ~ O9 ; “a ._ OBIT) Fe.0. | 45.0 + 102 b 2 6471 }Cav = | a 2 = 0.0536 MgO 2.25 i {i > 2 = 0.1125 2.8131 Let Z pounts of limestone to be added to 100 pounds of ash toform a slag in which SOi, = 0.85: then 3.3333 +- 0.00257 Z 2.5131 + 0.02161 Z Z 59.6 pounds limestone per 100 pounds ash hence 100 pounds fuel (containing 8.5 pounds; of ash) will require 5.0 pounds limestone. SiO, O85 - = 1.0), then 100 pounds fuel will re- Bases * quire 2.3 pounds limestone. The following is the method of com- puting the quantity of limestone for each ore, ‘‘A” being given as an example. The analysis of the other ores can be gath- ered from the table below. When dealing with the slag composition only one-half of the manganese is computed, under the assumption that the other half enters the iron: * A’ ore (100 pounds) fe = 48.5 per cent. and P. = 0. 080 per cent. 5 : 1.96 tons ore per ton of pig (pig 95 per cent. fe.). Cost of ore per ton of pig .. ............. $ P = 0.059 per cent. in pig. Molecular Equiva- Analysis. weight. lent. Si,0 = W.68 + ox4= . 1.3787 Al,O, = 480 + 2x6 = 02824 l46Mno 0.29 + ri) Z = (,0088 CaO 5.58 + 56x 2 = 0.1921 MgO 2.035 + 40 x 2 0.1175 0.6003 1.3787 + 0.90257 Z _ 0.35 0.6003 + U.O2161L Z Z= 54.9 pounds limestone per 100 pounds of ore. If base = 1.00, then 100 pounds of ore will re- quire 40.9 pounds limestone. Let it be supposed that the charge be composed of 12 barrows of fuel, 12 bar- rows of ore and 6 barrows of limestone, and say that the fuel (6000 pounds) will carry 9100 pounds of ore to be divided as follows: Ore. ree Le ae eer eee (Js tener ee ccccce. -deennee a aw erie 1500 Ct a EE ge eek a cea .. Law ME EE ST nicccdinadén <link: aeaeeed ou ueainases 1500 Ga UR vestieden, Seana - «-- S000 tid) ae Ai ee —— EE ERITH 10 THE TRON AGE January 1, 1891 How many pounds of limestone should be added to this ‘‘ore mixture” and fuel | 3 SiO, : to produce a slag in which = 0.85 ? Bases Turning to our tables, we find: Lime- stone. Lbs. 1K) Ibs, ** A’ ore will require 15 X 565. 325. 1500 Ibs. * B” ore will require 15 & 2.5 37.5 1500 Ibs. ** C ** ore will require 15 x 90.8 = 1362. 0 1500 Ibs. ** D” ore will require 15 x 13.7 205.5 | 8000 Ibs. “ E*’ ore will require 30 x 3.8 114.0 6060 pounds fuel will require 60 x 5.0 300. Hence limestone to be added = 2o44 or 474 pounds per barrow We can now calculate the composition of the slag by averaging the analyses of | the ores, and adding ‘the. slag forming in- gredients in the fuel and limestone used per 100 pounds of ore: Kinds of ore. SiO, Al,O; 2 barrows A.... ee 41.36 9.60 EE OS Sins ss acccseed oes teu 19.68 4.86 2barrowsC .... sca ieee 50.68 6.54 2 barrows D... ...... i905 11.00 1.22 DEE Dicccsse cee sieves 19.00 $.00 Divide by 12.. Average.. 66.7 pounds fuel per 100 pounds ore. 31 The slag is made up as follows: Lime- | Per- Ore. Fuel. | <4 Total cent- stone. age. Lbs. Lbs. Lbs. . bs. SiOg. = 11.81 Ti + 1.22 5.86) = 36.7 AlOs.. > 2.52) + 2.55 | +0 67|= B04 = 13.3 Mno.. > 0.43 tr ‘ork 0.43 1 ii 2.68) + ra i 9.15|= 11.91) = 27.5 MgoO..... = 2.83) + 0.13} + 6.32 9.29) = 21.5 20.28) +- 5. 59\4- 17.36 = 43.23) 100 | As soon as this mixture ‘‘ gets down” samples should be taken from every flush of cinders during one shift, and the SiO, | determined. Then whatever correction necessary should be in the amount of lime- stone. I have usually found the calcu- lated percentage of SiO, to be within 1 per cent. of the SiO, found by analysis; | hence little or no change should he made | in the quant