but few excavations or embankments, and no||route, and the assumed grades or inclinations, || slopes, in both excavations and embankments, stationary power, the elevations averaging only sometimes advantageously modified, and that being in the ratio of 14 to 1. Frequently, doubttwelve feet per mile. The engineer has also in consequence the estimates of cost (which less, steeper slopes will be admissible from the do not properly belong to the incipiency of op- greater tenacity of the soil-in which event made an estimate of the cost of the road pre-erations of this nature) are not intended to be there will be a correspondent reduction in the dicated upon this first survey, which is consid- otherwise than approximate. quantity of excavation; but I have thought it erably within the amount of capital of the comsafer to assume the slopes which I have stated, pany, and the estimate will no doubt be much and I therefore directed the calculations to be made accordingly. lessened by further surveys, as Capt. Swift, the assistant engineer, in his report accompanying Capt. McNeil's, remarks, as follows: cost of construction." Whenever streams are to be crossed, (and they are but few, and generally unimportant in their character,) if the structure is of such importance as to be classed as a viaduct, I have supposed it to be built, as for the most part in our country it is advisable they should be, of wood, supported on piers and abutments of substantial masonry. The comparatively few culverts required will uniformly be built of stone, for the construction of which materials abound. The railway I assume to be a single one, in the first instance, with occasional passing places, constructed similarly to that proposed for the Boston and Providence Railroad, with an iron edge-rail of sufficient strength to admit its supports at intervals of four feet. Nevertheless, if at this time we are not enabled to assert that the country offers greater facilities than those which, in the limited period allotted to the surveys, we have found to exist, we have the satisfaction to know that a railroad between Providence and Stonington, (a "In the preliminary surveys which have been work so important in its character that, in conmade, it cannot be expected that we have been nexion with the Boston and Providence railfortunate enough to select the most favorable road, which is now in rapid progress of conroute between Stonington and Providence. Instruction, it may be said on its completion to the absence of all knowledge of the topography have perfected the important avenue between of the intermediate country, it could not be sup-New-York and Boston,) is practicable under the posed that the first line which we might chance following favorable circumstances, to wit: to pursue should, upon more thorough exami- Pursuing in general a very direct course, nations, prove to be the best that could be found. and avoiding throughout its extent the occurIt is true that the results of one survey furnish rence of a single abrupt curvation, its total all material facts necessary to a determination length from the termination of the Boston and of the general character of the route, viz. dis- Providence Railroad, to Stonington, on Long tances, elevations, nature of ground, amount Island Sound, (from which point we know that of bridging, &c. It also furnishes much infor- throughout the year the safe navigation by mation which will be useful in future examina-steamboats remains uninterrupted,) would be Its maximum cost may be stated at $10,000 tions. It may be added, moreover, that the essay 473 to 48 miles, (as it shall be computed per mile; and if it shall be preferred, as may be timates of cost are predicated upon the data either through Shannock Hill or around it,) and deemed expedient, to substitute a lighter rail which were collected in running the experi- in traversing this distance we surmount a sum- with a continuous support on wood, an equally mental line, and it will readily be seen that eve- mit dividing the waters of the Pawcatuck, which effective railway, (the weight of the rail being ry improvement that can be made in the direc-empty themselves near Stonington, from those about 32 lbs. per yard,) may be constructed for tion of the route, will result in a saving in the which, flowing in the opposite direction, con- $7,000 to $7,500 per mile. tribute to the Narragansett Bay, elevated 200 feet above tide, or conforming in a measure to the undulations of the ground on either side of this summit, the total elevation to be overcome amounts (as will be seen on reference to the To John S. Crary, Esq. President of the New-memoir) to 293 feet,-or 302 feet, if we shall take York, Providence, and Boston Railroad Com- that which Captain Swift describes as the pany, New-York City: "south route," which, instead of being directSIR-In compliance with the wish ex-ed through a gap in Shannock Hill, passes 2. Single track of railway, with pressed by your Company in an application ad-around its southern extremity. dressed to the Honorable Secretary of War, for This elevation can, however, be so distributed, the aid of the United States' Engineer Depart- that throughout its extent your railroad may be ment in the examination of the country between adapted to the use of locomotive engines; and Stonington, Connecticut and Providence, Rhode the calculations of cost, based upon the suppoIsland, and the execution of the requisite sur-sition that it will be, in consequence exhibit a veys to determine the practicability of, and the far larger expenditure than would be required, general circumstances under which a railroad if occasionally, and but for short distances, onmay be constructed between those points, ly steeper inclinations (within, however, the Captain Swift, of the United States' Topogra- ability of a locomotive engine,) should be introphical Engineers, with the requisite number of duced. This will be apparent from a statement assistants, was, during the month of August of the inclinations within which the railroad last, assigned to that duty under my direction, would be graduated, (supposing even the trace and I have now the honor to submit to you, of the route shall not, as is highly probable it agreeably to the instructions of the Topogra- may be, materially improved,) which are as folphical Bureau at Washington, the results of lows, to wit:. the examinations and surveys alluded to. They will be found embodied in the accompanying descriptive memoir of the country by Captain Swift, which is illustrated by the following maps, in plan and profile, to wit: The following is the Report of Captain MCNEIL: BOSTON, March 2, 1833. 1st. A general map of the country between Stonington and Providence, exhibiting the routes surveyed, with those which have been suggested and may be worthy of further examination. 2d. Three sheets, which comprise a map of the routes surveyed, on an enlarged scale of inches to a mile. 4 14,75 miles level, and under 2 feet per mile. 7,00 13,66 3,81 66 7,19 66 66 66 66 13 66 06 1,36 66 66 20 66 "26 66 "34 66 Or the average inclination is about 12 feet per mile. On the first supposition, the approximate cost of a railroad from Providence to Stonington may be estimated as follows, to wit: 1. Formation of the road-bed for a double track of railway, including excavations, embankments, and masonry, or all the operations preparatory to the reception of the rails, 505,830 90 3. Land and fences, say Or substituting a lighter rail, with a continuous support on wooden string pieces, the cost may be assumed at: 1. Formation of road-bed, 3. Land, &c., as above, 505,830 90 360,000 00 50,000 00 4. Contingencies, &c. 10 per cent. 91,583 09 $1,007,413 99 WM. GIBBS MCNEIL, Captain U. S. T. Engineers. LOWELL, April 17, 1833. The length of the road, as will have been seen, we have assumed to be 473 or 48 miles, as the distance shall be computed either through Which is most respectfully submitted by, the gap of the Shannock Hill, or by passing sir, your obedient servant, around its southern extremity; but although in 3d. Two sheets, which exhibit the profile of the former case there would be a saving of three the routes on which the calculations of cost fourths of a mile in distance and a few feet inwill at this time be based; and referring to these clination, these advantages are acquired at a documents generally for details and descrip- cost which leads us unhesitatingly to prefer the tions of the country, which it will not in conse- longer route. Subsequent surveys may, howquence be requisite I should recapitulate. I ever, determine, and we think it probable they To the Editor of the American Railroad Journal: shall, as summarily as may be, present the will, that, even by winding around Shannock SIR,-You having given in the Railroad facts which pertain to the question, "under Hill, the total distance will not exceed 48 miles. Journal, Vol. 2, No. 14, Mr. Bulkley's descripwhat circumstances is a railroad practicable On this supposition I proceed to submit the tion of his Patent Guard Rail, with his remarks between Stonington and Providence?" following estimate, based upon the data to be Before I attempt, however, to answer this obtained from the accompanying memoir, on it, and solicited the opinions of engineers, question, I would premise, and desire that it be wherein I have inserted the cost of excavation, and as the importance of the subject demands borne in mind, that the surveys which have as embankment and masonry, or in other words, all the light which can be obtained, I will give yet been made are purely experimental in their all that pertains to the formation or graduation some of my thoughts on the subject. character, or such as necessarily precede those of the road-bed, the calculations of the quantity on which would subsequently be established of excavation or embankment having been furthe definite location or actual position of the nished me by Captain Swift. railroad-that various deviations may be expected to be made from the general trace of the for a double track, or to a width of 28 feet, the The road-bed is supposed to be graduated In his description he says, "The Guard Rail is constructed on an entirely new principle, facture, of two kinds of metal, namely, wrought being by combination in the process of manu and cast iron." Soon after malleable iron was as between 30 and 200 degrees, malleable iron the staples must be drawn and replaced with first used for rails, they were formed by com-expands or contracts most. If it be so at high such new ones as suit the new brooms. The frequent repetition of these operations, (as is bining wrought and cast iron, and the invention temperatures, and the wrought iron bar be so constructed that it cannot slip in the cast iron, patented. Some notice of this may be found the wrought iron bar, when the rail is cool, will evidently necessary,) not only exhausts a great in Strickland's Reports to "The Pennsylvania be strained longitudinally, and the cast iron deal of time, but materially injures the frame of In order to obviate these difficulties, Society for the Promotion of Internal Improve- which encloses it compressed longitudinally, the car. when the rail is not subjected to any extrane-I propose substituting screw bolts for the staments," page 26, and in Wood's Treatise on ous force. Hence the wrought iron bar may ples, terminating at one end with an oval. The Railroads, second edition, page 49, and in most be nearly or quite torn asunder without any shaft of these bolts being made to pass through the cross timber of the frame, the wood must be other books on railroads. If he had been extraneous force being applied to the rail. aware of this, I should have expected him to have shown in what his rail differs from any which has been tried. 66 Mr. Bulkley says that practical results in Eng-cut away so as to admit about half the ovals, land prove that the upper side of malleable iron then, when the broom handle is put into the ovals, rails are liable to destruction, "partly in con- turn the screws at the other end of the bolts sequence of the great weight of the wheels, until the handle is brought so closely in conI believe that most of those who have at- which, being rolled upon the rails, extends the tact with the frame as to hold it in its place. tempted this have not been sufficiently ac- laminæ composing their upper surfaces, and at When it is necessary to lower the broom, noquainted with the mechanical properties of the length causes those surfaces to break up in thing has to be done but to loosen the screws, scales." When malleable iron was first used put the broom to its place, and screw them up different kinds of iron. Mr. Bulkley says that, for rails, some engineers supposed it would be again. in the construction of rails, strength of a pecu- liable to the objection above-mentioned, and The above may be considered too simple to liar description is required, by which he means some have even said that practice proved it so. receive general attention, but I am of opinion resilience, or the power to resist percussion. There has now been sufficient experience in that if any persons engaged in railroad transthe use of malleable iron rails to put this ques-portation adopt it, they will thereby save both He says that his description of rail has probation at rest. Mr. Wood, in the second edition time and money. bly four fold more of this kind of strength than of his Treatise on Railroads, page 45, speaks If you consider it worthy your attention, you can be produced from either kind of metal, if thus: "It has been said by some engineers, that will oblige me by publishing it. AN OBSERVER. used separately, of equal weight. This seems, wrought iron rails exfoliate, or separate, in their [A drawing accompanied this communica by referring to the properties of the two kinds lamina, on that part which is exposed to the pressure of the wheel. This I pointedly deny, tion, but it came too late to have it engraved to of iron, to be impossible. The lower side of| as I have closely examined rails which have the rails have to resist a tensive force, or a been in use for many years, and on no part are appear in this number of the Journal: we regret this the less, as we think "An Observer's" deforce to draw the parts asunder. The tenacity such exfoliations to be seen." Mr. Bulkley says, Wrought metal is ob- scription is sufficiently explicit without it.] of wrought iron being much greater than that served to decay and become weakened in crusts of cast iron, the former, for this reason, cæteris of rust, when laid near the surface of the earth THE BRITISH IRON TRADE.-Great Briparibus, must be more suitable than the latter in damp situations." Some wrought iron rusts for this part of the rail. The force which acts very fast, but I do not think it generally oxy-tain has been particularly fortunate in posWhen mal- sessing inexhaustible mines of coal and iron on the upper side of the rail tends chiefly to dates much faster than cast iron. compress or crush it; therefore, that kind of leable iron was first used for rails, it was sup--two natural products which give the counposed by some people that its tendency to oxy- try a prodigious superiority over the adjacent iron would seem best for this part which can date would be a great objection to it; but ex- continental nations. By means of these vabear the greatest compressing force. The perience has proved the contrary. I will again luable materials, and the skill of the inhabimean strength of cast iron to resist a compress-quote Mr. Wood, as I know of no better authoing force is probably not much different from rity on this subject. He says, in the second tants, we are able to export hardware goods edition of his Treatise on Railroads, page 47, and machinery of every description, on the that of malleable iron, though there is much "On no malleable iron railway has oxydiza- most advantageous terms, to all parts of the difference in the various kinds both of mallea- tion, or rusting, taken place to any important world. From an early period the natives ble and cast iron. Tredgold says, in his trea-extent." have enjoyed a high reputation for the manuSufficient experiments and observations have facture of warlike weapons; and, what is tise on cast iron, that the greatest compressing force which cast iron can bear per square inch, not yet been made to determine, exactly, how justly esteemed a compliment to the people, it much faster cast iron is worn away by the achas more than once occurred that they have without producing a permanent alteration, is tion of the wheels on the rails, than wrought 15,300 pounds, and that good English mallea- iron; but it seems that cast iron wears off about supplied fire-arms, bayonets, swords, and daggers, to the very nations with which they are ble iron will bear 17,800 pounds per square five times as fast as wrought iron. inch without producing a permanent alteration: I am of opinion that malleable iron rails, such at war: thus furnishing instruments for their from which it seems there can be nothing as those of the Liverpool and Manchester Rail-own annoyance and destruction. gained in point of strength by making the up-road, are, in most cases, more safe, durable, per part of the rail of cast iron, though there and economical, than any rail composed wholly are many other properties, both of cast and or in part of cast iron yet brought before the The iron trade of England is one of the chief staples in the country, and gives employment to a vast body of laborers and arti malleable iron, which should be taken into ac-public. I have considered the chief of the sup- zans. Every where our observation is atcount in calculating accurately the strength posed advantages of the cast and malleable iron of bars—one is, that in most castings some rail; the other supposed advantages being detracted towards the combinations and results parts tend to expand or compress the other pendent on those already considered, need no parts, which is produced by unequal shrinking comment. in cooling. The interior part of square cast iron bars is usually strained by tension, while the outward part is compressed, when it is not To the Editor of the American Railroad Journal: subjected to any extraneous force. When such tral axis is between the centre of the bar and 66 can ade. of this extensive branch of traffic, and we U. A. B. find that there is even less to create astonishment in the multitude and variety of the proDOWNINGTON, April 6th, 1833. ducts, than in the exquisite perfection of the machinery employed-machinery seeming SIR,-In passing over several lines of rail- almost to usurp the functions of human intelbars are subject to transverse strain, the neu- road during the last three months, I have per- ligence. "No one, for instance," says a the compressed side, hence more than half of ceived that hickory brooms are almost univer-writer in the Quarterly Review, the metal acts by tension, and also acts at sally attached to the cars in front of the wheels, quately comprehend the mighty agency of the a greater mechanical advantage than if the so as to remove any dust or small stone from steam engine, who has not viewed the machineutral axis were in the centre of the bar: the rails that happen to be on them, and some-nery of some of our mining districts, where hence the strength of such bars to resist trans- times they are depended upon to remove light it is employed on a scale of magnitude of Their general adoption proves their power unequalled elsewhere. In Cornwall if the metal shrunk equally in cooling. This snows. unequal shrinking in cooling diminishes the utility. These brooms are generally attached especially, steam engines may be seen workstrength of a bar to resist a force which acts to the frame of the car, by means of staples. ing with a thousand horse power, and capable (according to a usual mode of estimating their merely by compression, or merely by tension. To this plan for attaching them there are seveperfection as machinery) of raising nearly Mr. Bulkley says, that when melted metal flows 50,000,000 pounds of water through the space round the bar of wrought iron, it causes the ral objections: when the brooms become worn wrought iron to expand, and contraction there-off at the bottom, it is necessary to set them of a foot, by the combustion of a single bushel fore becomes uniform in both cast and wrought lower; and in order to do this, the staples must of coal. No Englishman, especially destined iron. I am not aware that sufficient experi- be drawn, and, after the brooms are put to their to public life, can fitly be ignorant of these verse strain is much greater than it would be ments have been made to determine whether cast and wrought iron expand or contract proper places, driven up again, or, what is more great works and operations of art which are equally by equal changes of temperature, at common, broken off and replaced with new going on around him; and if time can be high temperatures; but at low temperatures,||ones. When new brooms are to be affixed, afforded in general education for Paris, Rome, and Florence, time is also fairly due to Man-Specification of Mr. Scrivenor's Patent for|| chester, Glasgow, Leeds, Birmingham, and Sheffield. Nor, speaking of the manufactures of England, can those be neglected which depend chiefly or exclusively on chemical processes. It may be conceded, that the French chymists have had their share in the suggestion of these processes; but the extent, the variety, and success with which they have been brought into practical operation in England, far surpass the competition of any other country. These are, perhaps, from their nature and from their frequent need of secrecy, the least accessible of our manufactures to common observation; yet they, nevertheless, offer much that is attainable and valuable. Connected with our manufactures are the great works of the civil engineer, which cover every part of the kingdom-the canals, roads, fig. 4, which is a transverse section, aa being the holes for the spikes or fastenings which hold it to the block or support; and I next proceed to shape the cheeks OP, more accurately to fit the under side of the rails, which if placed in the chair in its present state would have the appearance shown at fig. 5, and would be too unsteady for their pur. pose.. In order to effect this, and to form at the same time a proper recess in the cheek O, for the wedge or key, which is used to Fig. 1. A B represents a pair of cast-iron wedge or key up the ends of the rails tight rolls or rollers, which must be mounted in in the chair, I make use of a cold wrought or proper frames or bearings as usual in iron cast iron mandrel, as shown at figs. 6 and 7, in the following manner: Having heated the works; these said rollers must have a series of grooves of mendations in their peri- drel between the cheeks, OP, of the chair, chair again in the furnace, I place the manIt was lately computed that about 700,000 pheries corresponding with the several shapes and present it with the mandrel in it to pass tons of iron are annually made: Great Bri-which the metal is intended to take in its protain, a very large proportion of which are gress through these rollers, until it at length the produce of South Wales and Stafford-attains the exact shape to form the chairs or shire. In Scotland, 36,500 tons were, at the pedestals. Thus, for example, the grooves same time, made. The chief consumption at C D must be adapted to receive an ordiof this immense quantity of metal is in the nary short thick bar of wrought iron, say island itself, there being little more than about two feet long and about six inches 100,000 tons exported. The value of that square, properly heated for rolling, and, in which was exported was, for British iron fact, of a size adapted for these said grooves, £1,226,617, and for hardware and cutlery all which is well understood by persons ac£1,387,204. customed to roll iron. docks, bridges, piers, &c. : works which attest, more obviously than any other, the activity, power, and resources of the country.' through another pair of rollers, as shown at S The bar is first passed through the rollers The great seat of the iron manufacture in at C D, which causes it to assume the shape Scotland is at Carron, a place in Stirlingshire, shown at J. It is then passed in succession situated on the north banks of the river Car- through the other grooves on the rollers at ron, about three miles from the south shore of KK, LL, MM, and NN, whereby it succesthe Firth of Forth, and a short way north of sively takes the forms shown at E, F, G, and Falkirk. The Carron iron works, which are H. Having thus obtained a long bar of iron, reckoned one of the greatest wonders in of the form shown in section H, I next pro- fig. 8, which rollers press the cheeks OP North Britain, are the property of a charter-ceed to cut it into lengths for chairs, which close upon the mandrel, I; and when the ed company, established in 1760. They are I perform by means of a pair of mill shears, chair leaves these rollers it is complete ; and employed in smelting ores, and the manufac-shown at fig. 2; these shears may be worked if the mandrel be withdrawn, and the rail ture of all kinds of cast iron goods, whether used in war or agriculture, domestic economy, or any other purpose. Cannon, mortars, howitzers, and carronades of every description, are here made in the greatest perfection. The carronade now used in warfare was first made at Carron, and hence assumed its name. Shot and bomb shells of every sort and size are also made, and on a scale which rivals the manufactories of Germany a WP 2 now inserted in it, will have the appearance shown at fig. 9, being the recess or aperture 10 into which the wedge or key is to be driven to fix the rails firmly and steadily in their and Russia. This large establishment is in the ordinary manner, but must be provided places. The dotted lines in this figure show placed in the midst of a country, possessed of with steelings or jaws to receive the chair, the alteration in form which the chair has inexhaustible stores of the materials of its as shown at VW, otherwise the action of the experienced by passing through the rollers manufacture, and has every facility of export. shears in cutting off the lengths would be apt shown at fig. 8. Besides these qualifications, the country is to force the chair out of shape. It may be here Fig. 10 represents a wrought iron chair, rich in every species of produce, and able to as well to observe, that as the form of the made of more than one piece, and in this support a dense population. Including those chair would necessarily vary to suit the form chair the cheeks of the chair are made to fit employed in the works, and those engaged in of the rail to be used with it, and it would lead the rail by rivetting pieces of iron rolled to the mines and pits, with the individuals em-to an unnecessary variety of shapes if I did the proper shapes, to the cheeks of the chairs, ployed in the coasting and carrying trade, the not take one as a standard, for the purpose of after they leave the rollers at NN, fig. 1, in whole will amount to between 2,000 and 3,000 describing my invention, I have selected which case they will not require to be passed persons, who subsist directly by the works. that form of rail which I believe to be one through the rollers shown at fig. 8. Fig. 10, To a stranger, the approach to the establish- of the most approved and most generally in which is now under description, represents ment from the north, in a calm night, is strik-modern use, and need only state that chairs a chair in the state in which it is left by the ing and terrible, from the illumination of the may be made of wrought iron, on the same action of the rollers at NN, fig. 1, and as atmosphere, which is seen at a great distance, principle which I am now describing, to suit shown at fig. 4, the cheeks O P having plane the noise of the weighty hammers resounding any of the ordinary forms of rail now in use; sides, or being parallel to each other. This upon the anvils, the groaning of blast ma- but for the purposes of this specification I fig. 10 exhibits a section of the chair, in which chines, and the reflection of the flames in the shall confine my description to the form of S T represent pieces of rolled iron firmly reservoir which bounds the works on the chair required for the form of rail shown in secured to the insides of the cheeks O P, by north, as in a large mirror. The scene is section at fig. 3. rivetting, as aforesaid. much admired, and often resorted to in "the Having, in manner hereinbefore described, calm summer e'en," even by the local inhabi-cut the rolled bar into proper lengths for tants.-..ambers' Journal.] chairs, they will assume the form shown at a Fig. 11 exhibits it in this latter state, with wrought iron placed within it, and secured firmly by means of an iron wedge or key, driven tightly underneath the overhanging||Company, who stated, "that they (the Direc-were then applied upon the upper edge of the piece S, and pressing upon the shoulder of tors) had made an appropriation for renewing rail, it surely would be sustained on some printhe rail at Q. This plan of wrought iron wood rails, which were only in the fifth year ciple. If not on the principle of the arch, I should chair will be found useful when the lower of their use." It would be improper publicly like to know on what principle the weights part of the rail for which it is intended may to mention the name of any Company, in con- would be sustained; and I presume it will be be of any shape, differing from the ordinary nection with a circumstance of that nature, but admitted that the wrought iron rod, in such there could be no objection to mentioning the case, is on the right side for strength, in resistname of the Company to any individual who ing pressure. feels interested in furthering an inquiry on the subject. kind. 12 13 14 15 Again, Mr. S. states, "It is however a Guard Rail,' that is, when a superstructure of cast iron breaks, the wrought iron is to catch or prevent the fall; its useful effects, he remarks, depend not on the sure result of a principle, but on labor faithfully done in rivetting down the ends of the bar embedded in the castSo far from the remarks in the above quota Mr. S. in that communication has stated much in favor of wood rails; and made many remarks purporting to be in opposition to the "Guard Rail." Alluding, therefore, to wood rails, Mr. Sullivan states that "he has reason to think that timber can be applied in such wise ing." as to last thirty, perhaps fifty years." When he becomes enabled to satisfactorily establish tion being correct, I will merely remark that that point, he will be deemed to have discover-the rails, eight feet long, alluded to in my desed an important improvement. cription published, which were placed with sup But his views in allusion to the principle of porters at their ends only, and upon which ten the "Guard Rail," and of the effects produced tons at a single bearing were applied without in the uniting of wrought and cast iron, are to-affecting them, and without doubt will sustain tally at variance with practical results. Mr. twenty tons or more, have yet the wrought iron S. has not read my specification of the princi- rods projecting at the ends beyond the cast iron. The reason that the experiment was ple and manufacture of the "Guard Rail," which specification was predicated on pracmade without cutting off and rivetting the bolts, tical results-nor has he examined the cast- was because it was considered as depending on principle, and not on labor performed in Fig. 12 is a plan of a chair of the fullings in my possession; had he have done so, size, and fig. 13 a side view of it with part he would have been satisfied from occular demon-rivetting as stated by Mr. S., it being found in of a rail placed in it: and fig. 14 is the plan, stration, that the remarks touching those points, practice that the cast metal binds the wrought and fig. 15 the elevation, of another and" principle and manufacture," were made from so closely as to render rivets at the ends unbroader chair, calculated to receive the ends a misapprehension of the effects produced. In-necessary. The primary strength of the Rail, of two rails, and to hold them more firmly deed, my explanation was too brief to convey a therefore, is in the combination of the two than the narrower one shown before. kinds of metal: the lower edge of the cast iron, minute description: hence I remarked in my Now, whereas I claim as my invention the in full size for use, being secured from end to explanation, that "Rails made on this princisubstitution of wrought or malleable in the end by a wrought rod, which, as now applied, place of cast iron, in the construction of ple have been examined by many scientific genthose parts of iron railways called chairs tlemen, among whom were several eminent would require a distending force of some forty or pedestals, whether the same be made in engineers, and approved of by all of them. Atons to draw it apart endwise, and the action is one single piece or of separate pieces, riv. remark by one of those engineers was, that etted, or otherwise fastened together as here-in his opinion this discovery would be the means inbefore described; and such, my invention, of producing a revolution in the construction being to the best of my knowledge and be. of railroads.' An eminent Professor in this lief entirely new, I claim the exclusive right and privilege to my said invention. In witness whereof, &c. &c. [For the American Railroad Journal.] MR. EDITOR,-I perceive in the last number of your Journal a communication from Mr. Sul I per such, that it, the wrought iron rod, must be drawn endwise before a fissure can commence in the lower dge of the cast iron: and applied in that ma ner, the strength of the wrought rod alone will be sufficient to sustain safely twice or thrice the weight usually applied upon railroads, and may on the same principle be made of any required strength. city, whose opinion was solicited, remarked, R. BULKLEY. New Jersey Rail Road.-The Elizabethtown Journal states that a survey and estimate of the expense of this Rail Road has been submitted to the Commis The estimated cost of the road from Somerville to livan, which is commenced as follows, "Objections to Mr. Bulkley's Guard Rail, with some Suggestions on the Preservation of those of Timber;" and terminates as follows, "In cities, where the object is to have few supports, and One of the most singular views expressed by guard against shocks, it is highly probable it Mr. S., on the subject of the "Guard Rail," issioners, as follows:would be comparatively useful; (and adds,) in that sentence in which he opposes the idea Belvidere-a distance of about 45 miles-is $541,250; regret that the necessary defence of other meof the rail being strengthened on the principle or about $12,000 per mile. The branch from New thods should have given occasion for any reof the arch. He says, "If it comprehends the Hampton to Easton-14 miles at the same rate will marks against it. The claim is only too broad;" principle of the arch, it is an inverted one; and cost 168,000. The estimated cost of the road from Elizabethtown to Somerville-20 miles-was 200,The claim may indeed seem too broad for the force is on the wrong side for strength, 000, or 10,000 per mile. Making for the whole exsons who have favorite projects of their own. tent of the road and branches, a distance of 79 miles, which is in tension, not resistance, to pressure.' $909,250. This improvement runs entirely across but so far as relates to "necessary defence of In view of his error, I will suppose the cast the State of New Jersey, in its most fertile part, and other methods," I will, in reply, only remark,|| iron part of a "Guard Rail" to be broken cross-comes in close connexion with the agricultural and mineral wealth of Pennsylvania. that if other methods are affected by the publi- wise into short sections, each section of course cation of notorious facts, and by extracts from to have in its lower edge an aperture for the publications of others, the fault is not mine. My wrought iron rod to pass through; the wrought Miscellany notices the invention of Mr. Mcremarks in regard to the practical defects in iron rod to be passed through those sections, and Mullen, of Huntingdon county, in this state, wrought metal, were noted as extracts from an to be strongly rivetted at both ends: thus a rail of a machine of the above name. English publication; and my remark that "wood would be formed of cast iron sections, or seg-scribed as being turned by a crank, and rerails had, in this country, been observed so far ments, secured together in the lower edge by||quiring about as much power as a small to decay as to require renewing the fifth year," a wrought iron bolt or rod. If the ends of such a hand organ. It is capable of performing were not observations of my own, but by infor-rail were placed upon blocks and the edge con- the work of six expert knitters and adapted mation derived from a Director of a Railroad [taining the rod placed downwards, and if weights to the knitting of wool, cotton or silk. STOCKING KNITTER.-The Lancaster, Pa. It is de tion. A. B. C. Terms of the Table. Table of First Dif- Second Difference. 1 1 3 2 2 4 5 3 9 2 7 4 16 2 9 On Calculating by Machinery-Mr. Bab-||do; and, as I have had the advantage of see-slightly acquainted with that science, will bage's Plan. [From Partington's British |ing it actually calculate, and of studying its readily conceive that it is not impossible, by Cyclopædia.] construction with Mr. Babbage himself, I am attending to the following example. Let us The great Pascal was the first who suc-able to make this statement on personal ob-consider the subjoined table. This table is ceeded in reducing to pure mechanism theservation." It consists essentially of two the beginning of one in very extensive use, performance of a variety of arithmetical oper- parts, a calculating and a printing part, both which has been printed and reprinted very ations, and a description of the instrument by of which are necessary to the fulfilment of the frequently in many countries, and is called a which he effected this object is to be found in inventor's views, for the whole advantage table of square numbers. the fourth volume of the Machine Approuvees would be lost if the computations made by the of M. Gallon. In 1673, Sir Samuel Morland machine were copied by human hands and published an account of two different machines transferred to types by the common process. which he had invented, one for the perfor-The greater part of the calculating machinemance of addition and subtraction, and the ry, of which the drawings alone cover upother for that of multiplication, without how. wards of 400 square feet of surface, is alreaever developing their internal construction. dy constructed, and exhibits workmanship of About the same period the celebrated Leib. such extraordinary skill and beauty, that nothnitz, the Marquis Poleni, and M. Leupold, di-ing approaching to it has hitherto been witIn the printing part, less progress rected their attention to the subject, and in-nessed. vented instruments for accomplishing the has been made in the actual execution, in same purpose by different methods. Leib. consequence of the difficulty of its contrivance nitz published his plan in the Miscellanea Be- not for transferring the computations from rolensia of the year 1709, giving, however, the calculating part to the copper, or other only the exterior of the machine; and Poleni plate destined to receive them, but for giving communicated an account of his to the same to the plate itself that number and variety of work, but also explained its internal construc- movements which the forms adopted in printBoth of these machines, together with ed tables may call for in practice. that of Leupold, were subsequently described The practical object of the calculating enin the Theatrum Arithmetico-Geometricum of gine is to compute and print a great variety Any number in the table, column A, may the latter, published at Leipsic in 1727. We and extent of astronomical and navigation tabe obtained by multiplying the number which must not omit to mention the Abaque Rhab- bles, which could not otherwise be done with- expresses the distance of that term from the dologique of M. Perrault, inserted in the first out enormous intellectual and manual labor, commencement of the table by itself; thus volume of the work which we have referred and which, even if executed by such labor, 25 is the fifth term from the beginning of the to above, the Machines Approuvees, by the could not be calculated with the requisite ac- table, and 5 multiplied by itself, or by 5, is Paris Academy, which contains also an accuracy. Mathematicians, astronomers, and equal to 25. Let us now subtract each term count of a Machine Arithmetique of M. Les- navigators, do not require to be informed of of this table from the next succeeding term, pine, and of three distinct ones of M. Hille. the real value of such tables; but it may be and place the results in another column (B), rin de Boistissandeau. In 1735, Professor proper to state, for the information of others, which may be called first-difference column. Gersten, of Giessen, communicated to the that seventeen large folio volumes of logarith. If we again subtract each term of this firstRoyal Society of London a very detailed de- mic tables alone were calculated under the difference from the succeeding term, we find scription of an instrument of this nature which superintendence of M. Prony, at an enormous the result is always the number 2 (column C); he had invented, and the hint of which, he expense to the French government; and that and that the same number will always recur says, "I took from that of M. de Leibnitz, the British government regarded these tables in that column, which may be called the sewhich put me upon thinking how the inward to be of such national value, that they pro- cond-difference, will appear to any person structure might be contrived." posed to the French Board of Longitude, to who takes the trouble to carry on the table a Notwithstanding the skill and contrivance print an abridgment of them at the joint exfew terms further. Now, when once this is bestowed upon instruments of a nature simi- pense of the two nations, and offered to ad- admitted as a known fact, it is quite clear that, lar to that we have just described, their pow-vance £5000 for that purpose. But, besides provided the first term (1) of the table, the er is necessarily but very limited, and they logarithmic tables, Mr. Babbage's machine first term (3) of the first-difference, and the bear no comparison either in ingenuity or will calculate tables of the powers and pro-first term (2) of the second or constant diffemagnitude to the grand design conceived, and ducts of numbers, and all astronomical tables rence, are originally given, we can continue nearly executed, by Mr. Babbage. Their for determining the positions of the sun, moon, the table to any extent, merely by simple advery highest functions were but to perform the and planets; and the same mechanical prin- dition: for the series of first-differences may operations of common arithmetic; Mr. Bab-ciples have enabled him to integrate innume. be formed by repeatedly adding the constant bage's engine, it is true, can perform these rable equations of finite differences-that is, difference 2 to (3) the first number in column operations; it can also extract the roots of when the equation of differences is given, he B, and we then necessarily have the series numbers, and approximate to the roots of can, by setting an engine, produce at the end of odd numbers, 3, 5, 7, &c.; and again, by equations, and even to their impossible roots; of a given time any distant term which may successively adding each of these to the first but this is not its object. Its function, in con- be required, or any succession of terms com- number(1) of the table, we produce the square tradistinction to that of all other contrivances mencing at a distant point. numbers." for calculating, is to embody in machinery the On the means of accomplishing this, we Having thus thrown some light on the themethod of differences, which has never be- need make no apology for quoting Mr. Bab-oretical part of the question, Mr. Babbage fore been done; and the effects which it is bage's own words. "As the possibility of proceeds to shew that the mechanical execu. capable of producing, and the works which, performing arithmetical calculations by ma-tion of such an engine as would produce this in the course of a few years, we expect to see chinery may appear to non-mathematical rea- series of numbers is not so far removed it execute, will place it at an infinite distance ders too large a postulate, and as it is connec. from that of ordinary machinery as might be from all other efforts of mechanical genius. ted with the subject of the division of labor, I conceived. He imagines 3 clocks to be plaGreat as the power of mechanism is known shall here endeavor, in a few lines, to give ced on a table, side by side, each having only to be, yet we venture to say, that many of the some slight perception of the manner in which one hand, and a thousand divisions instead of most intelligent of our readers will scarcely this can be done; and thus to remove a small twelve hours marked on the face; and every admit it to be possible, that astronomical and portion of the veil which covers that apparent time a string is pulled, each strikes on a bell navigation tables can be accurately compu- mystery. That nearly all tables of numbers the numbers of the divisions to which the ted by machinery; that the machine can it- which follow any law, however complicated, hand points. Let it be supposed that two of self correct the errors which it may commit; may be formed, to a greater or less extent, the clocks, for the sake of distinction called and that the results, when absolutely free from solely by the proper arrangement of the sue- B and C, have some mechanism by which the error, can be printed off without the aid of hu- cessive addition and subtraction of numbers clock C advances the hand of the clock B one man hands, or the operation of human intelli- befitting each table, is a general principle, division for each stroke it makes on its own gence. "All this, however," says Sir David which can be demonstrated to those only who bell; and let the clock B by a similar contriBrewster, in his entertaining Letters on Na- are well acquainted with mathematics; but vance advance the hand of the clock A one tural Magic, “Mr. Babbage's machine can the mind, even of the reader who is but very division for each stroke it makes on its own |