 Section 3 of the Romance of Modern Mechanism. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. Recording by Kristen Edwards. The Romance of Modern Mechanism by Archibald Williams. Chapter 3, Workshop Machinery, Part 1. The lathe, planing machines, the steam hammer, hydraulic tools, electrical tools in the shipyard. When I first entered this city, said Mr. William Fairbairn, in an inaugural address to the British Association at Manchester in 1861, the whole of the machinery was executed by hand. There were neither planing, slotting, nor shaping machines. And with the exception of very imperfect lathe and a few drills, the preparatory operations of construction were affected entirely by the hands of the workmen. Now everything is done by machine tools, with a degree of accuracy which the unaided hand could never accomplish. The automaton, or self-acting machine tool, has within itself an almost creative power. In fact, so great are its powers of adaptation that there is no operation of the human hand that it does not imitate. If such things could be said with Justice 45 years ago, what would Mr. Fairbairn think? Could he see the wonderful machinery with which the present day workshop is equipped? Machinery as relatively superior to the devices he speaks of, as they were superior to the unaided efforts of the human hand. Invention never stands still. The wonder of one year is on the scrap heap of abandoned machines almost before another 12 months have passed. Some important detail has been improved to secure ease or economy in working, and a more efficient successor steps into its place. In his curious and original Arawan, Mr. Samuel Butler depicts a community which, from the fear that machinery should become too ingenious, and eventually drain away man's capacity for muscular and mental action, has risen in revolt against the automaton. Broken up all machines which had been in use for less than 270 years, with the exception of specimens reserved for the national museums, and reverted to hand labor. His treatment of the dangers attending the increased employment of lifeless mechanisms as a substitute for physical effort does not, however, show sympathy with the Arawanians. Since their abandonment of invention has obviously placed them at the mercy of any other race retaining the devices so laboriously perfected during the ages, and we, on our part, should be extremely sorry to part with the inanimate helpers which in every path of life render the act of living more comfortable and less toilsome. So dependent are we on machinery that we owe a double debt to the machines which create machines. A big factory houses the parents which send out their children to careers of usefulness throughout the world. We often forget in our admiration of the offspring, the source from which they originated. Our bicycles, so admirably adapted to easy locomotion, owe their existence to a hundred delicate machines. The express engine, hurrying forward over the iron way, is but an assemblage of parts which have been beaten, cut, twisted, planed, and otherwise handled by mighty machines, each as wonderful as the locomotive itself. But then we don't see these. This and following chapters will therefore be devoted to a few peeps at the great tools employed in the world's workshops. If you consider a moment, you will soon build up a formidable list of objects in which circularity is a necessary or desirable feature. Wheels, shafts, plates, legs of tables, walking sticks, pillars, parts of instruments, wire, and so on. The Hindu Turner, whose assistant revolves with a string of wooden blocks centered between two short spiked posts let into the ground while he himself applies the tool, is at one end of the scale of lathe users. At the other we have the workman who tends the giant machine slowly shaping the exterior of a 12 inch gun, a propeller shaft, or a marble column. All aim at the same object, perfect rotundity of surface. The artisans of the Middle Ages have left us in beautiful balusters and cathedral screens, ample proofs that they were skilled workmen with the turning lathe. At the time of the Huguenot persecutions, large numbers of French artificiers crossed the channel to England, bringing with them lathes which could cut intricate figures by means of wheels, eccentrics, and other devices of a comparatively complicated kind. The French had undoubtedly got far ahead of the English in this branch of the mechanical arts, owing no doubt to the fact that the French noblesse had condescended to include ternary among their aristocratic hobbies. With the larger employment of metal in all industries, the need for handling it easily is increased. Much greater accuracy generally distinguishes metal as compared to woodwork. In turning a piece of work on the old fashioned lathe, the workman applied and guided his tool by means of muscular strength. The work was made to revolve, and the turner, holding the cutting tool firmly upon the long straight guiding edge of the rest, along which he carried it, and pressing its point firmly against the article to be turned, was thus enabled to reduce its surface to the required size and shape. Some dexterous turners were able, with practice and carefulness, to execute very clever pieces of work by this simple means. But when the article to be turned was of considerable size, and especially when it was of metal, the expenditure of muscular strength was so great that the workman soon became exhausted. The slightest variation in the pressure of the tool led to an irregularity of surface, and with the utmost care on the workman's part, he could not avoid occasionally cutting a little too deep, in consequence of which he must necessarily go over the surface again to reduce the hole to the level of that accidentally cut too deep, and thus possibly the job would be altogether spoiled by the diameter of the article under operation being made too small for its intended purpose. Any modern worker is spared this labor and worried by the device known as the slide rest. Its name implies that it at once affords a rigid support for the tool, and also the means of traversing the tool in a straight line parallel to the metal face on which the work is being done. The introduction of the slide rest is due to the ingenuity of Mr. Henry Maudsley, who, at the commencement of the 19th century, was a foreman in the workshop of Mr. Joseph Brahma, inventor of the famous hydraulic press and locks which bear his name. His rest could be moved along the bed of the lathe by a screw and clamped to any position desired. Fellow workmen at first spoke derisively of Maudsley's go-cart, but men competent to judge its real value had more kindly words to say concerning it, when it had been adapted to machines of various types for planing as well as turning. Mr. James Naysmith went so far as to state that, its influence in improving and extending the use of machinery has been as great as that produced by the improvement of the steam engine in respect to perfecting manufacturers and extending commerce. In as much as without the aid of the vast accession to our power of producing perfect mechanism which it at once supplied, we could never have worked out into practical and profitable forms the conceptions of those masterminds who, during the last half century, have so successfully pioneered the way for mankind. The steam engine itself, which supplies us with such unbounded power, owes its present perfection to this most admirable means of giving to metallic objects the most precise and perfect geometrical forms. How could we, for instance, have good steam engines if we had not the means of boring out a true cylinder or turning a true piston rod or planing a valve face? It is this alone which has furnished us with the means of carrying into practice the accumulated results of scientific investigations on mechanical subjects. The screw cutting lay the SOA range that the slide rest is moved along with its tool at a uniform speed by gear wheels, actuated by the mechanism rotating the object to be turned. By changing the wheels, the rate of feed may be varied so that at every revolution the tool travels from 1.64 of an inch upwards along the surface of its work. This regularity of action adds greatly to the value of the slide rest and the screw device also enables the workman to chase a thread of absolutely constant pitch on a metal bar so that a screw cutting lathe is not only a shaping machine but also the equivalent of a whole armory of stocks and dies. Some lathes have rests which carry several tools held at different distances from its axis. The cuts following one another deeper and deeper into the metal in a manner exactly similar to the harvesting of a field of corn by a succession of reaping machines. The recent improvements in tool steel render it possible to get a much deeper cut than formerly without fear of injury to the tool from overheating. This results in a huge saving of time. For the boring of large cylinders, an upright lathe is generally used as the weight of the metal might cause a dangerous sag where the cylinder attached horizontally by one end to a facing plate. Huge wheels can also be turned in this type of machine up to 20 feet or more in diameter and where the crossbar carrying the tools is fitted with several tool boxes, two or more operations may be conducted simultaneously such as the turning of the flange, the boring of the axle hole and the facing of the rim sides. Perhaps the most imposing of all lathes are those which handle large cannon and propeller shafts such as may be seen in the works of Sir W.G. Armstrong, Whitworth and Company, of Mr. Victor's, Sons and Maxim and of other armament and shipbuilding firms. The Midvale Steel Company have in their shops at Hamilton, Ohio, a monster boring lathe which will take in a shaft 60 feet long, 30 inches in diameter and bore a hole from one end to the other, 14 inches in diameter. To do this, the lathe must attack the shaft at both ends simultaneously as a single boring bar of 60 feet would not be stiff enough to keep the hole cylindrical. The shaft is placed in a revolving chuck in the central portion of the lathe which has a total length of over 170 feet and supported further by two revolving ring rests on each side towards the extremities. With work so heavy, the feeding up of the tool to its surface cannot be done conveniently by hand control and the boring bars are therefore advanced by hydraulic pressure, a very ingenious arrangement ensuring that the pressure shall never become excessive. Perhaps the type of lathe most interesting to the layman is the turret lathe generally used for the manufacture of articles turned out in great numbers. The headstock, i.e. the revolving part which grips the object to be turned is hollow so that a rod may be passed right through it into the vicinity of the tools which are held in a hexagon turret, one tool projecting from each of its sides. When one tool has been finished with, the workman does not have the trouble of taking it out of the rest and putting another in its place, he merely turns the turret around and brings another instrument opposite the work. If the object, say a watercock, requires five operations performing on it in the lathe, the corresponding tools are arranged in their proper order around the turret. Stops are arranged so that as soon as any tool has advanced as far as is necessary, a trip action checks the motion of the turret, which is pulled back and given a turn to make it ready for the next attack. One of the advantages of the turret lathe, particularly of the automatic form which shifts around the tool box without human intervention, is its power of relieving the operator of the purely mechanical part of the work. Those who are familiar with the inside of some of our large workshops will have noticed men and boys who make the same thing all day and every day and are themselves not far removed from machines. The articles they make are generally small and very rapidly produced and the endless repetition of the same movements on the part of the operator is very tedious to watch and must be infinitely more so to perform. Such an occupation is not elevating and those engaged in it cannot take much interest in their work or become fitted for a better position. When this work is done by an automatic lathe, the machine performs the necessary operations and the man supplies the intelligence and by exercising his thinking powers becomes more valuable to his employers and himself. The introduction of new machines and methods generally has a stimulating effect on the whole shop, whatever the Erwonians might say. The hubs and spindles of bicycles are cut from the solid bar by these automata. The tender has merely to feed them with metal and they go on smoothing, shaping and cutting off until the material is all used up. The existence of such lathes largely accounts for the low price of our useful metal steeds at the present time. A great amount of shaping is now done by milling cutters in preference to firmly fixed edge tools. The cutter is a rod or disk which has its sides, end or circumference serrated with deep teeth shaped to the section of the cut needed. Revolving at a tremendous speed, it quickly bites its way into anything it meets just so far as a stop allows it to go. One of the most ingenious machines to which the milling tool has been fitted is the well-known Blanchard lathe which copies generally in wood repetitive work such as the stocks for guns and rifles. The lathe has two sets of centers, one for the copy, the other for the model, parallel on the same bed and turned at equal speeds and in the same direction by a train of gear wheels. The milling cutter is attached to a frame from which a disk projects and is pressed by a spring against the model. As the latter revolves its irregular shape causes the disk, frame and cutter to move towards or away from its center. And therefore towards or away from the center of the copy, which has all superfluities whisked off by the cutter. The frame is gradually moved along the model, reproducing in the rough block a section similar to the part of the model which it has reached. The self-centering chuck is an accessory which has proved invaluable for saving time. It may most easily be described as a circular plate which screws on to the inner end of the mandrel, the spindle imparting motion to the object being machined, and has in its face three slots radiating from the center at angles of 120 degrees. In each slot slides a stepped jaw, the underside of which is scored with concentric grooves engaging with a helical scroll turned by a key and worm gear acting on its circumference. The jaws approach or recede from the center symmetrically so that if a circular object is gripped its center will be in line with the axis of the lathe. Whether for gripping a tiny drill or large wheel, the self-centering chuck is indispensable. Not less important in engineering than the truly curved surface is the true plane in which, as Euclid would say, any two points being taken, the straight line between them lies wholly in that superfaces. The lathe depends for its efficiency on the perfect flatness of all areas which should be flat. The guides, the surface plates, the bottom and sides of the headstock, and above all of the slide rest. For making plane metal superfaces, a machine must first be constructed which itself is above suspicion, but when once built it creates machines like itself capable of reproducing others at infinitum. Many amateur carpenters pride themselves on the beautiful smoothness of the boards over which they have run their jack planes, yet as compared with the bed of a lathe their best work will appear very inaccurate. The engineer's planing machine in no way resembles its wooden relative. In the place of a blade projecting just a little way through a surface which prevents it from cutting too deep into the substance over which it is moving, we have a steel chisel very similar to the cutting tools of a lathe attached to a frame passing up and down over a bed to which the member holding the chisel is perfectly parallel. The article to be planed is rigidly attached to the bed and travels with it. Between every two strokes the tool is automatically moved sideways so that no two cuts shall be in the same line. After the whole surface has been roughed a finishing cutter is brought in action and the process is repeated with the business edge of the tool rather nearer to the bed. Joseph Clement, a contemporary of Babbage, Maudsley and Naismith, is usually regarded as the inventor of the planing machine. By 1825 he had finished a planer in which the tool was stationary and the work moving under it on a rolling bed. Two cutters were attached to the overhead crossrail so that travel in either direction might be utilized. The bed of the machine, on which the work was laid, passed under the cutters on perfectly true rollers or wheels, lodged and held in their bearings as accurately as the best mandrel could be and having set screws acting against their ends, totally preventing all end motion. The machine was bedded on a massive and solid foundation of masonry and heavy blocks, the support at all points being so complete as effectually to destroy all tendency to vibration with the object of securing full, round and quiet cuts. The rollers on which the planing machine traveled were so true that Clement himself used to say of them, if you were to put a paper shaving under one of the rollers it would at once stop the rest. Nor was this an exaggeration. The entire mechanism, notwithstanding its great size, being as true and accurate as a watch. Mr. Clement next made a revolving attachment for the bed in which bodies could be revolved under the cutter on an axis parallel to the direction of travel. According to the wish of the operator, the object was converted into a cylinder, cone or prism by its movements under the planing tool. So efficient was the machine that it earned its maker upwards of 10 pounds a day at the rate of about 18 shillings a square foot until rivals appeared in the field and finally reduced the cost of planing to a few pence for the same area. There are two main patterns of planes now in general use. The first follows the original design of Clement. The second has a fixed bed but a moving tool. Where the work is very heavy as in the case of armor plates for battleships, the power required to suddenly reverse the motion of a vast mass of metal is enormous, many times greater than the energy expended on the actual planing. For this reason the moving bed machines have had to be greatly improved and in some cases replaced by fixed bed planers. It is an impressive sight to watch one of these huge mechanisms reducing a rough plate weighing 20 tons or more to a smoothness which would shame the best billiard table. The machine which towers 30 feet into the air and completely dwarfs the attendant who has it as thoroughly under control as if it were a small file bites great shining strips 40 feet long maybe off the surface of the passive metal and leaves a series of grooves as truly parallel as the art of man can make them. There is no fuss, no sticking, no stop, no noise. The force of electricity or steam transmitted through wonderfully cut and arranged gear wheels is irresistible. The tool so hard that a journey through many miles of steel has no appreciable effect on its edge shears its way remorselessly over the surface which presently may be tempered to a toughness resembling its own. If you want to resharpen the tool it will be no good to attack it with any known metal but somewhere in the works there is a machine whose buzzing emery wheels are more than a match for it and rapidly grind the blunted edge into its former shape so that it is ready to flay another plate one skin at a time. Planing machines are of many shapes some have an upright on each side of the bed limiting the width of the work they can take. Others are open-sided one support of extra strength replacing the two enabling the introduction of a plate twice as broad as the bed. Others again are built on the verge of a pit so that they may cut the edges of an upended plate and make it fit against its fellow so truly that you could not slip a sheet of paper edgeways between them. Thus has man so frail and delicate in himself shaped metal till it can torture its kind to suit his will which he makes known to it by opening this valve or pulling on that lever. Not only does he flay it but pierces it through and through twists it into all manner of shapes hacks masses off as easily as he would cut slices from a loaf squeezes it in terrible presses to a fraction of its original thickness and otherwise so treats it that we are glad that our scientific observations have as yet discovered no sentience and the substance is reduced to our service. End of Section 3. Section 4 of the Romance of Modern Mechanism. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer please visit LibriVox.org. Recording by Kristen Edwards. The Romance of Modern Mechanism by Archibald Williams. Workshop Machinery. Part 2. The Steam Hammer. The Scandinavian god Thor was a marvelous blacksmith. Thursday should remind us weekly of Odin's son from whose hammer flashed the lightning and threw him a Vulcan toiling at his smithy in the crater of Vesuvius. In spite of the pictures drawn for us by pagan mythologists of their godsmiths we are left with a doubt whether these beings, if materialized, might not themselves be somewhat alarmed by the steam hammer which mere mortals wield so easily. The forge is without dispute the show place of a big factory where huge blocks of metal feel the heavy hand of steam. As children we watch the blacksmith at his anvil attracted and yet half terrified by the spark showers flying from a white hot horseshoe. And even the adult long used to startling sights might well be fascinated and dismayed by the terrific blows dealt on glowing ingots by the mechanical sledge. James Naysmith the inventor of this useful machine was the son of a landscape painter who from his earliest youth had taken great interest in scientific and mechanical subjects of all kinds. At fifteen he made a steam engine to grind his father's paints and five years later a steam carriage that ran many a mile with eight persons on it. After keeping it in action two months he says in an account of his early life to the satisfaction of all who were interested in it my friends allowed me to dispose of it and I sold it a great bargain after which the engine was used in driving a small factory. I may mention that in that engine I employed the waste steam to cause an increased draft by its discharge up the chimney. This important use of waste steam had been introduced by George Stevenson some years before though entirely unknown to me. This interesting peep at the infancy of the motor carriage reveals mechanical capabilities of no mean order in young James. He soon entered the service of Mr. Joshua Field Henry Maudsley's partner and in 1834 set up a business on his own account at Manchester. At this date the nearest approach to the modern steam hammer was the tilt hammer operated by horse water or steam power. It resembled an ordinary hand hammer on a very large scale but as it could be raised only a small distance above its anvil it became less effective as the size of the work increased owing to the fall being gagged. In 1837 Mr. Naismith interviewed the directors of the Great Western Steamship Company with regard to the manufacture of some unusually powerful tools which they needed for forging the paddle shaft of the Great Britain. As the invention of the steam engine had demanded the improvement of turning methods so now the increase in the size of steamboats showed the insufficiency of forging machinery. Mr. Naismith put on his thinking cap. Evidently the thing needed was a method for raising a very heavy mass of metal easily to a good height so that its great weight might fall with crushing force on the object between it and the anvil. How to raise it? Brilliant idea! Steam! In a moment Naismith had mentally pictured an inverted steam cylinder rested on a solid upright overhanging the anvil and a block of iron attached to its piston rod. All that would be necessary was to admit steam to the underside of the piston until the block had risen to its full height and to suddenly open a valve which would cut off the steam supply and allow the vapor already in the cylinder to escape. By the next post he sent a sketch to the company who approved his design heartily but were unable to use it since the need for the paddle shaft had already been nullified by the substitution of a screw as the motive power of their ship. Poor Naismith knew that he had discovered a good thing but British forge masters with a want of originality that amounted to sheer blind stupidity refused to look at the innovation. We have not orders enough to keep in work the forge hammers we have they wrote and we don't want any new ones however improved they may be. His invention therefore appeared doomed to failure. Help however came from France and the person of Mr. Schneider founder of the famous Crusoe ironworks notorious afterwards as the birthplace of the Boer Long-Thoms. Mr. Naismith happened to be away when Mr. Schneider and a friend called at the Manchester works but his partner Mr. Gaskell showed the French visitors round the works and also told them of the proposed steam hammer. The designs were brought out so that its details might be clearly explained. Years afterwards Naismith returned the visit and saw in the Crusoe works a crankshaft so large that he asked how it had been forged. By means of your steam hammer came the reply. You can imagine Naismith's surprise on finding the very machine at work in France which his own countrymen had so despised and his delight over its obvious success. On returning home he at once raised money enough to secure a patent protected his invention and began to manufacture what has been described as one of the most perfect of artificial machines and noblest triumphs of mind over matter that modern English engineers have developed. A few weeks saw the first a 30 hundred weight hammer at work. People flocked to watch its precision, its beauty of action and the completeness of control which could arrest it at any point of its descent so instantaneously as to crack without smashing a nut laid on the anvil. Its advantages were so obvious that its adoption soon became general and in the course of a few years Naismith's steam hammers were to be found in every well-appointed workshop both at home and abroad. Naismith's invention was improved upon in 1853 by Mr. Robert Wilson, his partner and successor. He added an automatic arrangement which raised the top or head automatically from the metal it struck so that time was saved and loss of heat to the ingot was also avoided. The beauty of the balance valve as it was called will be more clearly understood if we remember that the travel of the hammer is constantly increasing as the piece on the anvil becomes thinner under successive blows. Under the influence of this very ingenious valve every variety of blow could be dealt by simply altering the position of a tappet lever by means of two screws a blow of the exact force required could be repeated an indefinite number of times. It became a favorite amusement to place a wine glass containing an egg upon the anvil and let the block descend upon it with its quick motion and so nice was its adjustment and so delicate its mechanism that the great block weighing perhaps several tons could be heard playing tap, tap upon the egg without even cracking the shell when at a signal given to the man in charge down would come the great mass and the egg and glass would be apparently as Walter Savage Landor has it blasted into space. Later on Mr. Wilson added an equally important feature in the shape of a double action handgear which caused the steam to act on the top as well as on the bottom of the piston thus more than doubling the effect of the hammer. The largest hammer ever made was that erected by the Bethlehem Iron Company of Pennsylvania. The top weighed 125 tons. After being in use for three years the owners consigned it to the scrap heap as inferior to the hydraulic press for the manufacture of armor plate though it had cost them 50,000 pounds. They then erected in its stead for an equal sum of money a 14,000 ton pressure hydraulic press which fitly succeeds it as the most powerful of its kind in the world. The change was made for three reasons. First, that the impact of so huge a block of metal necessitates the anvil being many times as heavy and even then the shock to surrounding machinery may be very severe. Secondly, the larger the forging to be hammered the less is the reaction of the anvil so that all the force of the blow tends to be absorbed by the side facing the hammer whereas with a small bar the anvil's inertia would have almost as much effect as the actual blow. Thirdly, the blow of the hammer is so instantaneous that the metal has not time to flow properly and this leads to imperfect forgings. The surface of which may have been cracked. For very large work therefore the hammer is going out of fashion and the press coming in though for lighter jobs it is still widely used. Before leaving the subject we may glance at the double headed horizontal hammer such as is to be found in the forge shop of the Horwich Railway Works. Two hammers carried on rails and rollers advance in unison from each side and pound work laid on the support between them. Each acts as an anvil to the other while doing its full share of the work so that not only is a great deal of weight saved but shocks are almost entirely absorbed while the fact that each hammer need make a blow of only half the length of what would be required from a single hammer enables twice as many blows to be delivered in a given time. Hydraulic tools Before discussing these in detail we shall do well to trace the history of the Brahma Press which may be said to be their parent since the principal employed in most hydraulic devices for the workshop as also the idea of using water as a means of transmitting power under pressure are justly attributed to Joseph Brahma. If you take a dive into the sea and fall flat on the surface instead of entering at the graceful angle you intended you will feel for some time afterwards as if an enemy had slapped you violently on the chest and stomach. You have learned by sad experience that water which seems to offer so little resistance to a body drawn slowly through it is remarkably hard if struck violently. In fact, if enclosed it becomes more incompressible than steel without in any way losing its fluidity. We possess in water therefore a very useful agent for transmitting energy from one point to another. Shove one end of a column of water and it gives a push to anything at its other end but then it must be enclosed in a tube to guide its operation. By a natural law all fluids press evenly on every unit of a surface that confines them. You may put sand into a bucket with the bottom of cardboard and beat hard upon the surface of the sand without knocking out the bottom. The friction between the sand particles and the bucket sides entirely absorbs the blow but if water were substituted for sand and struck with an object that just fitted the bucket so as to prevent the escape of liquid the bottom and sides too would be ripped open. The writer of this book once fired a candle out of a gun at a hermetically sealed tin of water to see what the effect would be. Another candle had already been fired through an iron plate one quarter of an inch thick. The impact slightly compressed the water in the tin which gave back all the energy in a recoil which split the sheet metal open and flung portions of it many feet in the air but the candle never got through the side. This affords a very good idea of the almost absolute incompressibility of a liquid. We may now return to history. Joseph Brahma was born in 1748 at Barnsley in Yorkshire. As the son of a farm laborer the man life would probably have been to follow the plow had not an accident to his right ankle compelled him to earn his living in some other way. He therefore turned carpenter and developed such an aptitude for mechanics that we find him when 40 years old manufacturing the locks with which his name is associated and six years later experimenting with the hydraulic press. This may be described simply as a large cylinder in which works a solid piston of a diameter almost equal to that of the bore connected to a force pump. Every stroke of the pump drives a little water into the cylinder and as the water pressure is the same throughout the total stress on the piston end is equal to that on the pump plunger multiplied by the number of times that one exceeds the other in area. Suppose then that the plunger is one inch in diameter and the piston one foot and that a man drives down the plunger with a force of one thousand pounds then the total pressure on the piston end will be 144 times one thousand pounds but for every inch that the plunger has traveled the piston moves only one forty fourth of an inch thus illustrating the law that what is gained in time is lost in power and vice versa. The great difficulty encountered by Brahma was the prevention of leakage between the piston and the cylinder walls. If he packed it so tightly that no water could pass then the piston jammed. If the packing was eased then the leak recommenced. Brahma tried all matter of expedience without success. At last his foreman Henry Monslay already mentioned in connection with the lathe slide rest conceived an idea which showed real genius by reason of its very simplicity. Why not he said let the water itself give sufficient tightness to the packing which must be a collar of stout leather with an inverted U-shape section. This suggestion saved the situation. A recess was churned in the neck of the cylinder at the point formerly occupied by the stuffing box and into this the collar was set the edges pointing downwards. When water entered under pressure it forced the edges in different directions one against the piston the other against the wall of the recess with the degree of tightness proportioned to the pressure. As soon as the pressure was removed the collar collapsed and allowed the piston to pass back into the cylinder without friction. A similar device to turn to smaller things for a moment is employed in a cycle tire inflator a cup shaped leather being attached to the rear end of the piston to seal it during the pressure stroke though acting as an inlet valve for the suction stroke. What we owe to Joseph Brahma and Henry Monslay for their joint invention the honor must be divided like that of designing a steam hammer between Naismith and Wilson it would indeed be hard to estimate wherever steady but enormous effort is required for lifting huge girders, houses, ships for forcing wheels off their axles for elevators for compressing the boring shield of a tunnel for compressing hay wool, cotton, wood even metal for riveting, bending drilling steel plates there you will find some modification of the hydraulic press useful if not indispensable. However, as we are now prepared for consideration of details we may return to our workshop and see what water is doing there. Outside stands a cylindrical object many feet broad and high which can move up and down in vertical guides. If you peep underneath you'll notice the shining steel shaft which supports the entire weight of this tank or coffer filled with heavy articles stones, scrap iron etc. The shaft is the piston plunger of a very long cylinder connected by pipes to pumping engines and hydraulic machines it and the mass it bears up as a reservoir of energy. If the pumping engines were coupled up directly to the hydraulic tools whenever a workman desired to use a press, drill or stamp as the case may be he would have to send a signal to the engine man to start the pumps and another signal to tell him when to stop. This would lead to great waste of time and a danger of injuring the tackle from over driving. But with an accumulator there is always a supply of water at command for as soon as the RAM is nearly down the engines are automatically started to pump it up again. In short the accumulator is to hydraulic machinery what their bag is to bagpipes or the air reservoir to an organ. In large towns high pressure water is distributed through special mains by companies who make a business of supplying factories engineering works and other places where there is need for it though not sufficient need to justify the occupiers in laying down special pumping plant. Lunning can boast 5 central distributing stations where engines of 6500 HP are engaged in keeping 9 large accumulators full to feed 120 miles of pipes varying in diameter from 7 inches downwards. The pressure is 700 pounds to the square inch. Liverpool has 23 miles of pipes under 850 pounds pressure Manchester 17 miles under 1100 pounds to these may be added Glasgow, Hull, Birmingham, Geneva Paris, Berlin, Antwerp and many other large cities in both Europe and the United States. For very special purposes such as making metal forging pressures up to 12 tons to the square inch may be required. To produce this intensifiers are used i.e. presses worked from the ordinary hydraulic mains which pump water into a cylinder of larger diameter connected with the forging press. The largest English forging press is to be found in the open Shaw works of Sir W.G. Armstrong Whitworth and Company. Its duty is to consolidate armor plate ingots by squeezing preparatory to their passing through the rolling mills. It has one huge ram 78 inches in diameter into the cylinders of which water is pumped by engines of 4,000 HP under a pressure of 6,720 pounds to the square inch which gives a total ram force of 12,000 tons. It has a total height of 33 feet is 22 feet wide and 175 feet long and weighs 1,280 tons. On each side of the anvil is a trench fitted with platforms and machinery for moving the ingot across the ingot block. Two 100 ton electric cranes with hydraulic lifting cylinders serve the press. The Bethlehem works squeezer has two rams each of much smaller diameter than the Armstrong Whitworth but operated by 1,5 tons pressure to the square inch. It handles ingots of over 120 tons weight for armor plating. In 1895 Mr. William Corey of Pittsburgh took out a patent for toughening nickel steel plates by subjecting them while heated to a temperature of 2,000 degrees Fahrenheit to great compression which elongates them only slightly though reducing their thickness considerably. The heating of a large plate takes from 10 to 20 hours. It is then ready to be placed between the jaws of the big press which are about a foot wide. The plate is moved forward between the jaws after each stroke until the entire surface has been treated. At one stroke a 17 inch plate is reduced to 16 inches and subsequent squeezings give it a final thickness of 14 inches. Its length has meanwhile increased from 16 to 18 and a half feet in proportion while its breath has remained practically unaltered. A simple sum shows that metal which originally occupied 32 and 2 thirds cubic inches has now been compressed into 31 cubic inches. This alteration being affected without any injury to the surface a plate very tough inside and very hard outside is made. The plate is next reheated to 1,350 degrees and allowed to cool very gradually to a low temperature to anneal it. Then once again the furnaces are started to bring it back to 1,350 degrees when cold water is squirted all over the surface to give it a proper temper. If it bends and warps at all during this process a slight reheating and a second treatment in the press restores its shape. The hydraulic press is also used for bending or stamping plates in small manners of forms. You may see 8 inch steel slabs being quietly squeezed in a pair of huge dies until they have attained a semi-circular shape to fit them for the protection of a Manowar's big gun turret or thinner stuff having its ends turned over to make a flange or still slenderer metal stamped into the shape of a complete steel boat as easily as the tin smith stamps tartlet molds. Another workshop, a pair of massive jaws worked by water power are breaking up iron pigs into pieces suitable for the melting furnace. The manufacture of munitions of war also calls for the aid of this powerful ally. Take the field gun and its ammunition. The gun itself is a steel barrel hydraulically forged and afterwards wire wound. The carriage is built up of steel plates flanged and shaped in hydraulic presses. The wheels have their naves composed of hydraulically flanged and corrugated steel discs and even the tires are forced on cold by hydraulic tire setters the rams of which are powerful enough to reduce the diameter of the welded tire until the ladder tightly nips the wheel. The shells for the gun are punched and drawn by powerful hydraulic presses and the copper driving bands are fixed on the projectiles with hydraulic presses. Quick firing cartridge cases are capped, drawn and headed by a hydraulic press whose huge mass always impresses the uninitiated as absurdly out of proportion to the small size of the finished case. And finally the cordite firing charge is dependent on hydraulic presses for its density and shape. The press for placing the driving band on a shell is particularly interesting. After the shell has been shaped and its exterior turned smooth and true, a groove is cut round it near the rear end. Into this groove a band of copper is forced to prevent the leakage of gas from the firing charge past the shell and also to bite the rifling which imparts a rotary motion to the shell. The press for performing the operation has six cylinders and rams arranged spoke-wise inside a massive steel ring. The rams carrying concave heads which, when the full stroke is made, meet at the center so as to form a complete circle. Pressure is admitted says Mr. Petch to the cylinders by copper pipes connected up to a circular distributing pipe. The press takes water from the 700 pounds main for the first three-eighths of an inch of the stroke and for the last one eighth of an inch, water pressure at three tons per square inch is used. The total pressure on all the rams to band a six inch shell is only 600 tons but for a 12 inch shell no less than 2800 tons is necessary. Electric tools in a shipyard of late years electricity has taken a very prominent part in workshop equipment on account of the ease with which it can be applied to a machine the freedom from belting and overhead gear which it gives and its greater economy. In a lathe shop where only half the lathe may be in motion at a time the shafting and the belts for the total number is constantly whirling absorbing uselessly a lot of power if however a separate motor be fitted to each lathe the workman can switch it on and off at his pleasure. The New York Shipbuilding Company a very modern enterprise depends mainly on electrical power for driving its machinery in preference to belting air or water. Let us stroll through the various shops and note the uses to which the current has been harnessed. Before entering our attention is arrested by a huge gantry crane born by two columns which travel on rails from the cross girder or bridge 88 feet long hang two lifting magnets worked by 25 HP motors which raise the load at the rate of 20 feet per minute. Motors of equal power move the whole gantry along its rails over the great piles of steel plates and girders from which it selects victims to feed the maw of the shops. The main building is of enormous size covering with its single roof no less than 18 acres just imagine four acres of skylights and two acres of windows and you may be able to calculate the little glaziers bill that might result from a bad hail storm In this immense chamber are included the machine, boiler blacksmith, plate frame, pipe and mold shops, the general store rooms, the building ways and outfitting slips. The material which enters the plate and storage rooms at one end does not leave the building until it goes out as a part of the completed ship for which it was intended when the vessel is ready to enter service. There are installed in one main building and under one roof all the material and machinery necessary for the construction of the largest ship known to commerce and eight sets of ship ways built upon masonry foundations covered by roofs of steel and glass and spanned by cranes up to 100 tons lifting capacity are practically as much a part of the immense main building as the boiler shop or machine shop. A huge 100 ton crane of 121 foot span dominates the machine shop and ship ways at a height of 120 feet. It toys with a big engine or boiler picking it up when the riveteers caulkers and fitters have done their work and dropping it gently into the bowels of a partly finished vessel. A number of smaller cranes run about with their loads. Those which handle plates are like the big gantry already referred to, equipped with powerful electromagnets which fix like leeches on the metal and will not let go their hold until the current is broken by the pressing of a button somewhere on the bridge. Sometimes several plates are picked up at once and then it is pretty to see how the man in charge drops them in succession one here another there by merely opening and closing the switch very quickly so that the plate furthest from the magnets falls before the magnetism has passed out of the nearer plates. Another interesting type is the extension arm crane which shoots out an arm between two pillars grips something and pulls it back into the main aisle down which it travels without impediment. On every side are fresh wonders. Here is an immense rolling machine fed with plates 27 feet wide which bends the 1 1 8 inch thick metal as if it were so much pastry or turns over the edges neatly at the command of a 50 HP motor. There we have an electric plate planer scraping the surface of a sheet half the length of a cricket pitch. As soon as the stroke is finished the bed reverses automatically while the tool turns over to offer its edge to the metal approaching from the other side also quietly yet irresistibly done. Now mark these punches as they bite one and a quarter inch holes through steel plates over an inch thick one every two seconds. A man cutting wads out of cardboard could hardly perform his work so quickly and well. Almost as horribly resistless is the circular saw which eats its way quite unconcernedly through bars six inches square or snips lengths off steel beams. What is that strange looking machine over there? It has three columns which move on circular rails round a table in the center up and down each column passes a stage carrying with it a workman and an electric drill working four spindles. Look here comes a crane with a boiler shell the plates of which have been bolted in position. The crane lets down its load and up onto the table and trots off while the three workmen move their columns round till the twelve drills are opposite their work then a dozen twisted steel points ranged in three sets of four one drill above the other bite into the boiler plates opening out holes at mathematically correct intervals all down the overlapping steam plates. This job done the columns move round the boiler and their drills pierce at first near the lower edge then near the upper. The crane returns grips the cylinder and bears it off to the riveters who are waiting with their hydraulic presses to squeeze the rivets into the holes just made and shape their heads into neat hemispheres. As it swings through the air the size of the boiler is dwarfed by its surroundings but if you had put a rule to it on the table you would have found that it measured twenty feet in diameter and as many in length. A few months hence furnaces will rage in its stomach and cause it to force tons of steam into the mighty cylinders driving some majestic vessel in the Atlantic. We pass giant laze busy on the propeller shafts huge boring mills which slowly smooth the interior of the cylinder planers which face the valve slides and we arrive I-weary at the launching ways where an ocean liner is being given her finishing touches then we begin to moralize that six hundred foot floating palace is a concretion of parts shaped, punched cut, planed, board fixed by electricity where does man come in? Well, he harnessed the current he guided it, he said do this and it did it does not that seem to be his fair share of the work? End of Section 4 Section 5 of the Romance of Modern Mechanism This is the LibriVox recording All LibriVox recordings are in the public domain For more information or to volunteer please visit LibriVox.org Recording by Stephen Seidel The Romance of Modern Mechanism by Archibald Williams Chapter 4 Portable Tools If the mountain won't come to Muhammad, says the proverb Muhammad must go to the mountain This is as true in the workshop as outside Muhammad being the tool the mountain the work on which it must be used With the increase in size of machinery and engineering material methods half a century old do not in many cases suffice especially at a time when commercial competition has greatly reduced the margin of profits formerly expected by the manufacturer Take the case of a large shaft which must have a slot cut along it on one side to accommodate the key wedge which holds an eccentric for moving esteem valves of a cylinder or a screw propeller so that it cannot slip The mass weighs perhaps 20 tons One way of doing the job is to transport the shaft under a drill that will cut a hole at each end of the slot area and then to turn it over to the planer for the intermediate metal to be scraped out This is a very toilsome and expensive business in the use of costly machinery which might be doing more useful work and the sacrifice of much valuable time Inventors have therefore produced portable tools which can perform work on big bodies just as efficiently as if it had been done by larger machinery in a fraction of the time and at greatly reduced cost To quote an example the cutting of a key way of the kind just described by big machines perhaps a whole day whereas the light portable easily attached miller now generally used bites it out in 90 minutes Pneumatic tools The best known of these is the pneumatic hammer It consists of a cylinder inside of which moves a solid piston having a stroke of from half an inch to six inches air is supplied through flexible tubing from a compressing pump the piston beats on a loose block of metal carried in the end of the tool which does the actual striking The piston suddenly decreases in diameter at about the center of its length leaving a shoulder on which the air can work to affect the withdrawal stroke By a very simple arrangement of airports the piston is made to act as its own valve As the plane sided the piston as a greater area than that of the piston rod fits the striking movement is much more violent than the return Under a pressure of several hundred pounds to the square inch the pneumatic hammer delivers upwards of 7,000 blows per minute The quick succession of comparatively gentle taps having the effect of a much smaller number of heavier blows For the flat hammer head can be substituted a curved die for riveting or a chipping chisel or a caulking iron to close the seams of boilers The riveter is particularly useful for ship and bridge building work where it is impossible to apply a hydraulic tool A skilled workman will close the rivet heads as fast as his assistant can place them in their holes Certainly in less than half the time needed for swing hammer closing Even more effective proportionately is the pneumatic chipper has seen one cut a strip off the edge of a half inch steel plate at the rate of several inches a minute To the uninitiated beholder it would seem impossible that a tool weighing less than two stone could thus force its way through solid metal The speed of the piston is so high that, though it scales but a few pounds, its momentum is great enough to advance the chisel a fraction of an inch and the individual advances following one another with inconceivable rapidity soon totaled up into a big cut Automatic chisels are very popular with ornamental masons as they lend themselves to the sculpturing of elaborate designs in stone and marble Their principle modified to suit work of another character is seen in percussive rock drills such as the Ingersoll Sergeant In this case the piston are solid and the air is let into the cylinder by means of slide valves operated by tapets which the piston strikes during its movements. Some types of the rock drill are controllable as to the length of their stroke so that it can be shortened while the entry of the hole is being made and gradually increased as the hole deepens For perpendicular boring the drill is mounted on a heavily weighted tripod, the inertia of which effectively damps all recoil from the shock of striking For horizontal work and sometimes for vertical the support is a pillar wedged between the walls of the tunnel or shaft An ingenious detail is the rifle bar which causes the drill to rotate slightly on its axis between every two strokes so that it may not jam The drills are light enough to be easily erected and dismantled and compact so that they can be used in restricted and out of the way places while there's simplicity entails little special training on the part of the workmen With pneumatic and other power drills the cost of piercing holes for explosive charges is reduced to less than one quarter that of jumping with a crowbar and sledge hammers With a hand method two men are required, usually more One man to hold, guide and turn the drill and the other or others to strike with hammers The machine, striking a blow far more rapidly than can be done by hand reduces the number of operators to one man and perhaps his helper So durable is the metal of these wonderful little mechanisms that the delivery of 360,000 blows daily for months even though each is given with a force of perhaps half a ton fails to wear them out Or at most only necessitates the renewal of some minor and cheap part The debt that civilization owes to the substitution of mechanical for hand labor will be fully understood by anyone who is conversant with the history of tunnel driving and mining Another application of pneumatics is seen in the device for cutting off the ends of stables of locomotive boilers It consists of a cylinder about 15 inches in diameter the piston of which operates a pair of large nippers capable of sharing half inch bars The whole apparatus weighs but three quarters of a hundred weight yet its power is such that it can trim bolts 40 times as fast as a man working with a hammer and coal chisel and more thoroughly Then there is the machine for breaking the short bolts which hold together the outer and inner shells of the water jacket round a locomotive furnace A threaded bar along which travels a nut as a hook on its end to catch the bolt The nut is screwed up to make the proper adjustment and a pneumatic cylinder pulls on the hook with a force of many tons easily shearing through the bolt We must not forget the pneumatic borer for cutting holes in wood or metal or enlarging holes already existing The head of the borer contains three little cylinders set at an angle of 120 degrees to rotate the drill opening automatically to admit air at very high pressures behind the pistons Any carpenter can imagine the advantage of a drill which has merely to be forced against its work the movement of a small lever by the thumb doing the rest Next on the list comes the pneumatic painter which acts on much the same principle as the scent spray Mechanical painting first came to the fore in 1893 when the huge Chicago exposition provided many acres of surfaces which had to be protected from the weather or hidden from sight The following description of one of the machines used to replace handwork is given in Cassier's magazine Quote The paint is atomized and sprayed on to the work by a stream of compressed air From a small air compressor the air is led through flexible hose to a paint tank which is provided with an airtight cover and clamping screws The paint is contained in a pot which can be readily removed and replaced by another when a different color is required The arrangement of interchangeable tins is also important as facilitating easy cleaning The container is furnished with a semi rotary stirrer the spindle passing through a stuffing box in the cover and ending in a handle by which the whole thing complete may be carried about necessarily fixed or stationary but the paint tank connected to it by the single air hose can be moved close to the work while the length of the hose from the tank to the nozzle gives the freedom of movement necessary Air pressure is admitted to the tank by a bottom valve and forces the paint up an internal pipe and along a hose from the tank to the spraying nozzle to which air pressure is also led by a second hose The nozzle is practically an injector of special form The flow of paint at the nozzle is controlled by a small plug valve and spring lever on which the operator keeps his thumb while working and which on release closes automatically When it is required to change from one color to another or to use a different material such as varnish the can previously in use is removed in air or if necessary paraffin oil is blown through the length of hose which supplies the paint until it is completely clean The writer then mentions as an instance of the machine's efficiency that it has covered a 30 feet by 8 feet boiler in less than an hour and that at one large bridge yard a 70 feet by 6 feet girder with all its projecting parts was coated with boiled oil in 2 hours a job which would have occupied the brush the whole day to execute Apart from saving time the machine produces a surface quite free from brush marks and easily reaches surfaces and intricate moldings which are difficult to get at with a brush The pneumatic sand jet is used for a variety of purposes for cleaning off old paint or the weathered surface of stonework for polishing up castings and forging after they have been brazed in a cycle factory you will find the sand jet hard at work on the joints of cycle frames which must be cleared of all roughness before they are fit for the enameler The writer a few days before penning these lines watched a jet removing London grime from the face of a large hotel Down the side streets stood a steam engine busily compressing air which was led by long pipes to the jet situated on some lofty scaffolding The rapidity with which the flying grains scoured off smoke deposits attracted the notice of a large crowd which gazed with upturned heads at the white and stones. Its peculiarity about the jet is that it proves much more effective on hard material than on soft as the latter by offering an elastic surface robs the sand of its cutting power. After merely mentioning the curve or forcing sand into foundry molds we pass to the pneumatic sandpapering machine which may be described briefly as a revolving disc carrying a circle of sandpaper on its face revolved between guards which keep it flat to the work. The disc flies around many hundreds of times per minute rapidly wearing down the fibrous surface of the wood it touches. When the coarse paper has done its work a cloth is substituted to produce the finished needful for painting. End of section number 5 Section 6 of The Romance of Modern Mechanism This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer please visit LibriVox.org Recording by Emanuel Zornberg. The Romance of Modern Mechanism by Archibald Williams Chapter 5 The Pedrail Have you ever watched carefully a steam roller's action on the road when it is working on newly laid stones? If you have you noticed that the stones, gravel, etc. in front of the roller moved with a wave-like engine so that the engine was practically climbing a never-ending hill. No wonder then that the mechanism of such a machine needs to be very strong and its power multiplied by means of suitable gearing. Again, suppose that an iron-tired vehicle traveling at a rapid pace meets a large stone. What happens? Either the stone is forced into the ground or the wheel must rise over it. In either case, there will be a jar to the vehicle and a loss of propulsive power. Do not all cyclists know the fatigue of riding over a bumpy road, fatigue to both muscles and nerves. As regards motors and cycles, the vibration trouble has been largely reduced by the employment of pneumatic tires which lap over small objects and when they strike large ones, minimize the shock by their buffer-like nature. Yet there is still a great loss of power and if pneumatic-tired vehicles suffer, what must happen to the solid, snorting inelastic traction engine? On hard roads it rattles and bumps along pulverizing stones crushing the surface. When soft ground is encountered insink the wheels because their bearing surface must be increased until it is sufficient to carry the engine's weight. But by the time that they are 6 inches below the surface there will be a continuous vertical belt of earth 6 inches deep to be crushed down incessantly by their advance. How much more favorably situated is the railway locomotive or truck? Their wheels touch metal at a point but a fraction of an inch in length. Consequently, there is nothing to hamper their progression. So great is the difference between the rail and the road that experiment has shown that whereas a pull from 8 to 10 pounds will move a ton on rails an equal weight requires attractive force of 50 to 100 pounds on the ordinary turnpike. In order to obviate this great wastage of power, various attempts have been made to provide a road locomotive with means for laying its own track as it proceeds. About 40 years ago Mr. Boydell constructed a wheel which took its own rail with it the rails being arranged about the wheel like a hexagon round a circle so that as the wheel moved it always rested on one of the hexagon sides, itself flat on the ground. This device had two serious drawbacks. In the first place, the plates made a rattling noise which has been compared to the reports of a maxim gun. Secondly, though the contrivance acted fairly well on level ground it failed when uneven surfaces were encountered. Thus, if a brick lay across the path, one end of a plate rested on the brick, the other on the ground behind and the unsupported center had to carry a sudden, severe strain. Furthermore, the plates being connected at the angles of a hexagon could not tilt sideways with the result that breakages were frequent. Of late years another inventor Mr. J. B. Diploc has come forward with an invention which bids fair to revolutionize heavy road traffic. At present though it has reached a practical stage and undergone many tests satisfactorily, it has not been made absolutely perfect for the simple reason that no great invention jumps to finality all at once. Are not engineers still improving the locomotive? The ped rail as it has been named signifies a rail moving on feet. Mr. Diploc observing that a horse has for its weight attractive force much in excess of the traction engine took a hint from nature and conceived the idea of copying the horse's foot action. The reader must not imagine that here is a return to the abortive and rather ludicrous attempts at a walking locomotive made many years ago when some engineers considered it proper that a railway engine should be propelled by legs. Mr. Diploc's device not merely propels but also steps i.e. selects the spot on the ground which shall be the momentary point at which propulsive force shall be exerted. To make this clearer consider the action of a wheel. First, we will suppose that the spokes any number you please are connected at the outer ends by flat plates. As each angle is passed the wheel falls flop onto the next plate the greater the number of the spokes the less will be each successive jar or step and consequently the perfect wheel is theoretically one in which the sides have been so much multiplied as to be infinitely short. A horse has practically two wheels, its front legs one, its back legs the other. The shoulder and hip joints form the axles and the legs the spokes. As the animal pulls the leg on the ground advances at the shoulder past the vertical position and the horse would fall forwards where it not for the other leg which has been advanced simultaneously. Each step corresponds to our many sided wheel falling onto a flat side and the hammer hammer on the hard high road is the horsey counterpart of the metallic rattle. On rough ground a horse has a great advantage over a wheeled tractor because it can put its feet down on the top of objects of different dimensions and still pull. A wheel cannot do this and as we have seen a loss of power results. Our inventor therefore created in his ped rail a compromise between the railway smoothness and ease of running and the selective and accommodating powers of a quadruped. We must now plunge into the mechanical details of the ped rail which is strictly speaking a term confined to the wheel alone. Our illustration will aid the reader to follow the working of the various parts. In a railway we have A. Sleepers on the ground B. Rails attached to the sleepers C. Wheels rolling over the rails In the ped rail the order reckoning upwards is altered. On the ground is the ped or movable sleeper carrying wheels over which a rail attached to the moving vehicle glides continuously. The principle is used by anyone who puts wooden rollers down to help him move heavy furniture about. Of course the peds cannot be put on the ground and left behind. They must accompany their rollers over the rails. We will endeavor to explain in simple words how this is affected. To the axles of the locomotive is attached firmly a flat vertical plate parallel to the sides of the firebox. Pivoted to it top and bottom at their centers are two horizontal rocking arms and these have their extremities connected by two shaped bars or cams their convex edges pointing outwards away from the axle. Powerful springs also join the rocking arms and tend to keep them in a horizontal position. Thus we have a powerful frame which can oscillate up and down at either end. The bottom arm is the rail on which the whole weight of the axle rests. The rotating and moving parts consist of a large flat circular case the sides of which are a few inches apart. Its circumference is pierced by 14 openings provided with guides to accommodate as many short siding spokes which are in no way attached to the main axle. Each spoke is shaped somewhat like a tuning fork. In the V is a roller wheel and at the tip is a pad or foot. As the case revolves the tuning fork spokes pass as it were with a leg on each side of the framework referred to above. The wheel of each spoke being the only part which comes into contact with the frame. Strong springs hold the spokes and rollers normally distance from the wheels center. It must now be stated that the object of the framework is to thrust the rollers outwards as they approach the ground and slide them below the rail. The side pieces of the frame are as will be noticed C figure 3 eccentric i.e. points on their surfaces are at different distances from the axle center. This is to meet the fact that the distance from the axle to the ground is greater in an oblique direction than it is vertically. And therefore, for three spokes to be carrying the weight at once two of them must be more extended than the third. So then a spoke is moved outward by the frame till its roller gets under the rail and as it passes off it it gradually slides inwards again. It will be obvious to the reader that if the pegs were attached inflexibly to the ends of their spokes they would strike the ground at an angle and of course be badly strained. Now Mr. Diplock meant his pegs to be as like feet as possible and come down flat. He therefore furnished them with ankles that is ball and socket joints so that they could move loosely on their spokes in all directions. And as such a contrivance must be protected from dust and dirt the inventor produced what has been called a crustacean joint on account of the resemblance it bears to the overlapping armor plates of a lobster's tail. The plates which suggest very thin quotes are made of copper and can be renewed at small lengths. The first joint made takes up all wear automatically and renders the plates noiseless. This detail cost its inventor much work. The first joint made represented an expenditure of 6 pounds but now thanks to automatic machinery any number can be turned out at 3s 6d each. The word about the feet a wheel has 14 of these they are 11 inches in diameter at the tread and sold with rubber in 8 segments with strips of wood between the segments to prevent suction in clay soil. The segments are held together by a malleable cast iron ring around the periphery of the feet and a tightening core at the center These wearing parts being separate from the rest of the foot are easily and cheaply renewed and repairs can be quickly affected if necessary when on the road. The surface in contact with the ground being composed of the three substances metal, wood and rubber which all take a bearing provides a combination of materials adapted to the best adhesion and wear on any class of road or even on no road at all Motive power is transmitted by the machinery to the wheel axle from that to the casing from the casing to the sliding spokes As there are alternately 2 and 3 feet simultaneously in contact with the ground the power of adhesion is very great much greater than that of an ordinary traction engine This is what professor Heelshaw says in a report on a ped rail tractor quote The weight of the engine is spread over no less than 12 feet each one of which presses upon the ground with an area immensely greater probably as much as 10 times greater than that of all the wheels of an ordinary traction engine taken together on a hard road upon a soft road all comparison between wheels and the action of these feet ceases the contact of each of the feet of the ped rail is absolutely free from all slipping action and attains the absolute ideal of working being merely placed in position without sliding to take up the load and then lifted up again without any sliding to be carried to a new position quote end quote it is necessary that the feet should come down flat on the ground if they struck it at all edgeways they would sprain their ankles otherwise probably break off at the ball joint mechanism was therefore introduced by which the feet would be turned over as they approached the ground and be held at the proper ready for the step without the aid of a special diagram it would be difficult to explain in detail how this is managed and it must suffice to say that the chief feature is a friction clutch worked by the roller of the foots spoke to the onlooker the manner in which the ped rail crawls over obstacles is almost weird the rider was shown a small working model of a ped rail propelled along a board covered with bits of cork wood etc the axle of the wheel scarcely moved upwards at all and had he not actually seen the obstacles he would have been inclined to doubt their existence an ordinary wheel of equal diameter took the obstructions with a series of bumps and bounds that made the contrast very striking extreme instance of the ped rail's capacity would be afforded by the ascent of a flight of steps c figure 4 in such a case the three peds carrying the weight of an axle would not be on the same level that makes no difference because the frame merely tilts on its top and bottom pivots the front of the rail rising to a higher level than the back end and the back spokes are projected by the rail much further than those in front so that the engine is simply levered over its rollers up an inclined plane similarly in descending the front spokes are thrust out the furthest and the reverse action takes place with so many moving parts everything must be well lubricated or the wear would soon become serious the feet are kept properly greased by being filled with a mixture of black lead and grease of suitable quality which requires renewal at long intervals only the sliding spokes rollers and friction clutches are all lubricated from one central oil chamber through a beautiful system of oil tubes which provides a circulation of the oil throughout all the moving parts the central oil chamber is filled from one orifice and holds a sufficient supply of oil for a long journey we may now turn for a moment from the ped rail itself to the vehicles to which it is attached here again we are met by novelties for in his engines Mr. Diplock has so arranged matters that not only can both front and back pairs of wheels be used as drivers but both also take part in the steering as may be imagined many difficulties had to be surmounted before this innovation was complete but that it was worthwhile is evident from the small space in which a double steering tractor can turn thanks to both its axles being movable and from the increased power another important feature must also be noticed is the axles can both tip vertically so that when the front left wheel is higher than its fellow the left back wheel may be lower than the right back wheel in short flexibility and power are the ideals which Mr. Diplock has striven to reach how far he has been successful may be gathered from the reports of experts Professor Heelshaw FRS says the Pedrail constitutes in my belief the successful solution of a walking machine which whilst obviating the chief objections to the ordinary wheel running upon the road can be made to travel anywhere where an ordinary wheel can go and in many places where it cannot at the same time it has the mechanical advantages which have made the railway system a phenomenal success it constitutes in my belief the solution of one of the most difficult mechanical problems and deserves to be considered as an invention quite apart from any particular means by which it is actuated whether it is placed upon a self-propelled carriage or a vehicle drawn by any agency mechanical or otherwise the way in which all four wheels are driven simultaneously so as to give the maximum pulling effect by means of elastic connection is in itself sufficient to mark the engine as a most valuable departure from common practice hitherto this driving of four wheels has never been successfully achieved partly because of the difficulty of turning the steering wheels and partly because until the present invention of Mr. Diplock and behind wheels would act against each other a defect at first experienced and overcome by the inventor in his first engine end quote on January 8th 1902 Mr. Diplock tried an engine fitted with two ordinary wheels behind and two ped rails in front the authority quoted above was present at the trials and his opinion will therefore be interesting quote the points which struck me immediately were 1. the marvelous ease with which it started into action 2. the little noise with which it worked another thing which I noticed was the difference in the behavior of the feet and wheels the feet did not in any way seem to affect the surface of the road throwing down large stones the size of the fist into their path the feet simply set themselves to an angle in passing over the stones and did not crush them whereas the wheel coming after invariably crushed the stones and moreover distorted the road surface coming to the top of the hill I made the ped rail walk first over three inch planks then six inch and finally over a nine inch bulk one could scarcely believe on witnessing these experiments that the whole structure was not permanently distorted and strained whereas it was evidently within the limits of play allowed by the mechanism as a proof of this the dip block engine walked down to the works and I then witnessed its ascent of a lane beside the engineering works which had ruts eight or ten inches deep and was a steep slope this lane was composed in places of the softest mud and whereas the wheels squeezed out the ground in all directions the feet of the ped rails set themselves at the angles of the rut where it was hard or walked through the soft and yielding mud without making the slightest disturbance around and ground I came away from that trial with the firm conviction that I had seen what I believe to be the dawn of a new era in mechanical transport end quote Mr. Diplock does not regard the ped rail as an end in itself so much as a means to an end this the development of road born traffic for very long distances which must be covered in a minimum of time the railway will hold its own but there is a growing feeling that unless the railways can be fed by subsidiary methods of transport more effectively than at present and unless remote county districts whether it would not pay to carry even a light railway are brought into closer touch with the busier parts our communications cannot be considered and we are not getting the best value out of our roads for many classes of goods cheapness of transportation is of more importance than speed witness the fact that coal is so often sent by canal rather than by rail here then is the chance for the ped rail tractor and its long train of vehicles fitted with ped rail wheels which will tend to improve the services they travel over Mr. Diplock sets out in his interesting book a new system of heavy goods transport on common roads a scheme for collecting goods from branch routes on to main routes where a number of cars will be coupled up and towed by powerful tractors with ordinary four wheeled trucks it is difficult to take a number round a sharp corner since each truck describes a more sudden circle than its predecessor the last often endeavoring to climb the pavement four wheeled would therefore be replaced by two wheeled trucks provided with special couplings to prevent the cars tilting while allowing them to turn cars so connected would follow the same track round a curve the body of the car would be removable and of a standard size it could be attached to a simple horse frame for transport into the fields there the farmer would load his produce and when the body was full it would be returned to the road picked up by a crane attached to the tractor swung on to its carriage and wheels and taken away to join the other cars by making the bodies of such dimensions as to fit three into an ordinary railway truck they could be entrained easily on reaching their destination another tractor would lift them out fit them to wheels and trundle them off to the consumer by this method there would be no breaking bulk of goods required from the time it was first loaded till it was exposed to the market for sale these things are of course in the future of more present importance is the fact that the war office has from the first taken great interest in the new invention which promises to be of value for military transport over ground either rough or boggy trials have been made by the authorities with encouraging results that daring writer Mr. H.G. Wells has in his land ironclads pictured the ped rail taking an offensive part in warfare huge steel plated forts mounted on ped rails and full of heavy artillery and machine guns sweep slowly across the country towards where the enemy has entrenched himself the forts are impervious alike to shell and bullet but as they cross ditch or hillock in their gigantic stride their artillery works havoc among their opponents who are finally forced to an unconditional surrender even if the ped rail is not made to carry weapons of destruction we can after our experiences with horse flesh in the Boer war understand how important it may become for commissariat purposes the feats which it has already performed market as just the locomotive to tackle the rough country in which baggage trains often find themselves to conclude with a more peaceful use for it when fresh country is opened up gears must often pass before a proper high road can be made yet there is great need of an organized system of transport with their ordinary traction engines or carts even horses could scarcely penetrate the ped rail tractor thanks to its big flat feet which give it as someone has remarked the appearance of a cross between a traction engine and an elephant will be able to push its way at the forefront of advancing civilization at home we shall have good reason to welcome the rail if it frees us from those terrible corrugated tracks so dreaded by the cyclist and to bless it if it actually beats our roads down into a greater smoothness than they now can boast end of section 6