Discoveries and Inventions of the Nineteenth Century
Part 15
The distance between the rails in Great Britain is 4 ft. 8½ in., that width having been adopted by George Stephenson in the construction of the earlier lines. Brunel, the engineer of the Great Western, adopted, however, in the construction of that railway, a gauge of 7 ft., with a view of obtaining greater speed and power in the engines, steadiness in the carriages, and increased size of carriages for bulky goods. The proposal to adopt this gauge gave rise to a memorable dispute among engineers, often called “The Battle of the Gauges.” It was stated that any advantages of the broad gauge were more than compensated by its disadvantages. The want of uniformity in the gauges was soon felt to be an inconvenience to the public, and a Parliamentary Committee was appointed to consider the subject. They reported that either gauge supplied all public requirements, but that the broad gauge involved a great additional outlay in its construction without any compensating advantages of economy in working; and, as at that time 2,000 miles of railway had been constructed on the narrow gauge, whereas only 270 miles were in existence on the broad gauge, they recommended that future railways should be made the prevailing width of 56½ in. The Great Western line had engines, bridges, tunnels, viaducts, &c., on a larger scale than any other railway in Britain. The difference of gauge was after a time felt to involve so much inconvenience that lines which adopted the 7–ft. gauge have since relaid the tracks at the more common width. At the present day we find the Great Western Railway completely reconstructed on the narrow gauge system, in order that trains may run without interruption in connection with other lines.
The wheels of railway carriages and engines differ from those of ordinary carriages in being fastened in pairs upon the axles, with which they revolve (see Fig. 45). The tire of the wheel is conical, the slope being about 1 in 20; that is, in a wheel 5 in. broad the radius of the outer edge is ¼ in. less than that of the inner; and the rails are placed sloping a little inwards. The effect of this conical figure is to counteract any tendency to roll off the rails; for if a pair of wheels were shifted a little to one side, the parts of the tires rolling upon the rails being then of unequal circumference, would cause the wheels to roll towards the other side. The conical shape produces this kind of adjustment so well that the flanges do not in general touch the rails. They act, however, as safeguards in passing over curves and junctions. In curves the outer line of rails is laid higher than the inner, so that in passing over them the train leans slightly inwards, in order to counteract what is called the centrifugal force, to which any body moving in a curve is subject. This so-called force is merely the result of that tendency which every moving body has to continue its motion in a straight line. A very good example of the effect of this may be seen when a circus horse is going rapidly round the ring. The inclination inwards is still more perceptible when a rider is standing on the horse’s back, as shown in Fig. 46. The earth’s attraction of gravity is pulling the performer straight down, and the centrifugal force would of itself throw her outwards horizontally. The resultant or combined effect of both acts is seen in the exact direction in which she is leaning, and it presses her feet on the horse’s back, the animal itself being under similar conditions. It is obvious that the amount of centrifugal force, and therefore of inward slope, will increase with the speed and sharpness of the curve, and on the railways the rails are placed so that the slope counteracts the centrifugal force when the train travels at about the rate of twenty miles per hour.
A very important part of the mechanism of a railway is the mode of passing trains from one line of rails to another. Engines and single carriages are sometimes transferred by means of _turn-tables_, but the more general plan is by _switches_, which are commonly constructed as shown in Fig. 47. There are two rails, A and B, tapering to a point and fixed at the other end, so that they have sufficient freedom to turn horizontally. A train passing in the direction shown by the arrow would continue on the main line, if the points are placed as represented; but if they be moved so that the _long tongue_ is brought into contact with the rail of the main line, then the train would run on to the side rails. These _points_ are worked by means of a lever attached to the rod, C, the lever being either placed near the rails, or in a _signal-box_, where a man is stationed, whose sole duty it is to attend to the points and to the signals. The interior of a signal-box near an important junction or station is shown in Fig. 48, and we see here the numerous levers for working the points and the signals, each of these having a connection, by rods or wires, with the corresponding point or signal-post. The electric telegraph is now an important agent in railway signalling, and in a signal-box we may see the bells and instruments which inform the pointsman whether a certain section of the line is “blocked” or “clear.” The signals now generally used on British railways are made by the semaphore, which is simply a post from which an arm can be made to project. When the driver of the train sees the arm projecting from the left-hand side of the post, it is an intimation to him that he must stop his train; when the arm is dropped half-way, so as to project 45° from the post, it is meant that he must proceed cautiously; when the arm is down the line is clear. These signals, of course, are not capable of being seen at night, when their place is supplied with lamps, provided with coloured glasses—red and green—and also with an uncoloured glass. The lamp may have the different glasses on three different sides, and be turned round so as to present the required colour; or it may be made to do so without turning, if provided with a frame having red and green glasses, which can be moved like spectacles in front of it. The meanings of the various coloured lights and the corresponding semaphore signals are these:
| White _All right_ Go on. ↿ Green _Caution_ Proceed slowly. ┓ Red _Danger_ Stop.
A very clear account of the mode of working railway signals on what is now called the _block system_, together with a graphic description of a signal-box, was given in a paper which appeared some years ago in “The Popular Science Review,” from the pen of Mr. Charles V. Walker, F.R.S., the telegraph engineer to the South-Eastern Railway Company, who was the first to organize an efficient system of electric signalling for railways. We may remark that the signalling instruments on the South-Eastern line, and indeed on all the lines at the present day, address themselves both to the ear and to the eye, for they consist of—first, bells, on which one, two, or more blows are struck, each series of blows having its own particular meaning; and, second, of a kind of miniature signal-post, with arms capable of being moved by electric currents into positions similar to those of the arm of an actual signal-post, so that the position of the arms is made always to indicate the state of the line. One arm of the little signal-post—the left—is red, and it has reference to _receding_ trains; the other—viz., the right—arm is white, and relates to _approaching_ trains. Mr. Walker thus describes the signalling:
“The ordinary position of the arms of the electro-magnetic telegraph semaphores will be down; that is to say, when the line is clear of all trains, and business begins, say in early morning, all the arms will be down, indicating that no train is moving. When the first train is ready to start, say from Charing Cross, the signalman will give the proper bell-signal to Belvidere—two, three, or four blows, according as the train is for Greenwich, for North Kent, or Mid-Kent, or for the main line; and the Belvidere man will acknowledge this by one blow on the bell in reply, and without raising the Charing Cross red or left arm. This is the signal that the train may go on; and when the train has passed, so that the Charing Cross man can see the tail lights, he gives the out signal a second time, which the Belvidere man acknowledges, at the same time raising the red arm at Charing Cross, behind the train, and so protecting it until it has passed him at Belvidere, when he signals to that effect to Charing Cross, at the same time putting down the red arm there, as an indication that the line is again clear. While these operations are going on for down trains, others precisely similar, but in the reverse direction, are going on for up trains.... One and the same pressure on the key sends a bell signal and raises or depresses the semaphore arm as the case may require, a single telegraph wire only being required for the combined system, as for the more simple bell system.” In one of the signal-boxes on the South-Eastern line, Mr. Walker states, on a certain day 650 trains or engines were signalled and all particulars accurately entered in a book, the entries requiring the writing down of nearly 8,000 figures: an illustration of the amount of work quietly carried on in a signal-box for the advantage and security of the travelling public.
Mr. Walker also gives us a peep into the inside of one of the signal-boxes, thus: “The interior of a large signal-box exhibits a very animated scene, in which there are but two actors, a man and a boy, both as busy as bees, but with no hurry or bustle. The ruling genius of the place is the strong, active, intelligent signalman, standing at one end of the apartment, the monarch for the time being of all he surveys. Immediately before him in one long line, extending from side to side, is a goodly array of levers, bright and clean from constant use and careful tending, each one labelled for its respective duty. Before him to the right and left are the various electro-magnetic semaphores, each one in full view and adjusted in position to the pair of roads to which it is appropriated, and all furnished with porcelain labels. Directly in front of him is a screen, along which are arranged the various semaphore keys; and on brackets, discreetly distributed, are the bells and gongs, the twin companions each of its own semaphore. Before the screen are the writing-desk and books, and here stands the youngster, the ministering spirit, all on the alert to take or to send electric signals and to record them, his time and attention being devoted alternately to his semaphore keys and to his books, being immediately under the eye and control of the signalman. This is no place for visitors, and the scenes enacted here have little chance of meeting the public gaze; indeed, the officers whose duties take them hither occasionally are only too glad to look on, and say as little as may be, and not interrupt the active pair, between whom there is evidently a good understanding in the discharge of duties upon the accurate performance of which so much depends. Looking on, the man will be seen in command of his rank and file: signals come, are heard and seen by both man and boy; levers are drawn and withdrawn, one, two, three, or more; the arms and the lamps on the gigantic masts outside, of which there are three, well laden, are displayed as required, distant signals are moved, points are shifted and roads made ready; telegraph signals are acknowledged; and on looking out—for the box is glazed throughout—trains are seen moving in accordance with the signals made; and on the signal-posts at the boxes, right and left—for here they are within easy reach of each other—arms are seen up and down in sympathy with those on the spot, and with the telegraph signals that have been interchanged. There is no cessation to this work, and there is no confusion in it; one head and hand directs the whole, so that there are no conflicting interests and no misunderstandings; all is done in perfect tranquillity, and the great secret is that one thing is done at a time. All this, which is so simple and so full of meaning to the expert, is to the uninitiated intricate and vague; and though he cannot at first even follow the description of the several processes, so rapidly are they begun and ended, yet, as the cloud becomes thin, and his ideas become clearer, he cannot fail to be gratified, and to be filled with admiration at the great results that are brought about by means so simple.”
Most of the carriages used on railways are so familiar to everyone that it is unnecessary to give any description of them. We give a figure of one which, though of early type, has special features of interest, being the well-designed Travelling Post Office, Fig. 49. In such vans as that here represented letters are sorted during the journey, and for this purpose the interior is provided with a counter and with pigeon-holes from end to end. When the train stops bags may, of course, be removed from or received into the van in the ordinary manner; but by a simple mechanism bags may be delivered at a station and others taken up while the train continues its journey at full speed. A bar can be made to project from the side of the carriage, and on this the bag is hung by hooks, which are so contrived that they release the bag when a rod, projecting from the receiving apparatus, strikes a certain catch on the van. The bag then drops into a netting, which is spread for its reception; and in order to receive the bags taken up, a similar netting is stretched on an iron frame attached to the van This frame is made to fold up against the side of the carriage when not in use. When the train is approaching the station where the bag is to be taken up, this frame is let down, and a projecting portion detaches the bags, so that they drop into the net, from which they are removed into the interior of the vehicle. These travelling post offices are lighted with gas, and are padded at the ends, so that the clerks may not be liable to injury by concussions of the carriages.
England has had to borrow from the United States not a few hints for such adaptations and appliances as tend to promote the comfort and convenience of travellers by rail, especially on what we insularly call long journeys. Some of these vehicles on the American railways are luxurious hotels upon wheels; they contain accommodation for forty persons, having a kitchen, hot and cold water, wine, china and linen closets, and more than a hundred different articles of food, besides an ample supply of tablecloths, table napkins, towels, sheets, pillowcases, &c. Then there are other Pullman inventions, such as the “palace” and the “sleeping” cars, in which the traveller who is performing a long journey makes himself at home for days, or perhaps for a week, as, for instance, while he is being carried across the American continent from ocean to ocean at the easy rate of twenty miles an hour on the Pacific and other connecting lines. Mr. C. Nordhoff, an American writer, giving an account of his journey to the Western States, writes thus: “Having unpacked your books and unstrapped your wraps in your Pullman or Central Pacific palace car, you may pursue all the sedentary avocations and amusements of a parlour at home; and as your housekeeping is done—and admirably done—for you by alert and experienced servants; as you may lie down at full length, or sit up, sleep, or wake at your choice; as your dinner is sure to be abundant, very tolerably cooked, and not hurried; as you are pretty certain to make acquaintances in the car; and as the country through which you pass is strange and abounds in curious and interesting sights, and the air is fresh and exhilarating—you soon fall into the ways of the voyage; and if you are a tired business man or a wearied housekeeper, your careless ease will be such a rest as certainly most busy and overworked Americans know how to enjoy. You write comfortably at a table in a little room called a ‘drawing-room,’ entirely closed off, if you wish it, from the remainder of the car, which room contains two large and comfortable armchairs and a sofa, two broad clean plate-glass windows on each side (which may be doubled if the weather is cold), hooks in abundance for shawls, hats, &c., and mirrors at every corner. Books and photographs lie on the table. Your wife sits at the window sewing and looking out on long ranges of snow-clad mountains or on boundless ocean-like plains. Children play on the floor or watch at the windows for the comical prairie dogs sitting near their holes, and turning laughable somersaults as the car sweeps by. The porter calls you at any hour you appoint in the morning; he gives half an hour’s notice of breakfast, dinner, or supper; and while you are at breakfast, your beds are made up and your room or your section aired. About eight o’clock in the evening—for, as at sea, you keep good hours—the porter, in a clean grey uniform, comes in to make up the beds. The two easy-chairs are turned into a berth; the sofa undergoes a similar transformation; the table, having its legs pulled together, disappears in a corner, and two shelves being let down furnish two other berths. The freshest and whitest of linen and brightly-coloured blankets complete the outfit; and you undress and go to bed as you would at home.”
An important general truth may find a familiar illustration in the subject now under notice. The truth in question may be expressed by saying that, in all human affairs, as well as in the operations of nature, the state of things at any one time is the result, by a sort of growth, of a preceding state of things. And in this way it is certainly true of inventions, that they never make their appearance suddenly in a complete and finished state—like Minerva, who is fabled to have sprung from the brain of Jupiter fully grown and completely armed; but rather their history resembles the slow and progressive process by which ordinary mortals attain to their full stature. We have already seen that railways had their origin in the tramways of collieries; and, in like manner, the railway carriage grew out of the colliery truck and the stage coach; for when railway carriages to convey passengers were first made, it did not occur to their designers that anything better could be done than to place coach bodies on the frame of the truck; and accordingly the early railway carriages were formed by mounting the body of a stage coach, or two or three such bodies side by side, on the timber framework which was supported by the flanged wheels. The cut, Fig. 56, is from a painting in the possession of the Connecticut Historical Society, and it represents the first railway train in America on its trial trip (1831), in which sixteen persons took part, who were then thought not a little courageous. Here we see that the carriages were regular stage coaches, and the same was the case in England. But it is very significant that, to this day, the stage coach bodies are traceable in many of the carriages now running on English lines, especially in the first-class carriages, where, in the curved lines of the mouldings which are supposed to ornament the outside, one may easily recognize the forms of the curved bodies of the stage coaches, although there is nothing whatever, in the real framing of the timbers of the railway carriage, which has the most distant relation to these curves. Then again, almost universally on English lines, the old stage coach door-handles are still retained on the first-class carriages, in the awkward flat oval plates of brass which fold down with a hinge. Many other points might be named which would show the persistence of the stage coach type on the English railways. The cut, Fig. 56, proves that the Americans set out with the same style of carriages; but North America, as compared with the Old World, is _par excellence_ the country of rapid developments, and there carriages, or cars, as our Transatlantic cousins call them, have for a long time been made with numerous improvements, and in forms more in harmony with the railway system, than the conservatism of English ideas, still cleaving to the stage coach type, permitted to be attempted in this country.
Railway travellers in the United States had long enjoyed the benefit of comforts and convenience in the appointments of their carriages long before any change had been effected in the general arrangements of the vehicles provided by the railway companies in England. It is now indeed a considerable number of years since this state of things has been altered in the older country; as all the great lines, following the example of the Midland Company, who first adopted the Pullman cars, have constructed luxurious vehicles in which every elegance and comfort are placed within the reach of the English traveller, and these improvements are highly appreciated by all who have long journeys to make by day or night.
The elegance and comfort of the arrangements are almost too obvious to require description. We see the luxuriously padded chairs, which, by turning on swivels, permit the traveller to adjust his position according to his individual wishes, so that he can, with ease, place his seat either to gaze directly on the passing landscape, or turn his face towards his fellow-travellers opposite or on either side. The chairs are also provided with an arrangement for placing the backs at any required inclination, and the light and refined character of the decorations of the carriage should not escape the reader’s notice. Pullman Cars of another kind, providing sleeping accommodation for night journeys, are also in use on the Midland line, and they are fitted up with the same thoughtful regard to comfort as the Parlour Car.
The great engineering feats which have been accomplished in the construction of railways are numerous enough to fill volumes. We give, therefore, only a short notice of one or two recently constructed lines which have features of special interest, concluding with a brief account of such remarkable constructions as the railway by which the traveller may now go up the Rigi, and the railways which ascend Vesuvius and Mt. Pilatus.
_THE METROPOLITAN RAILWAYS._