CHAPTER I

ENGINEERING REMINISCENCESCHAPTER IBirth, Parentage and Education. Experience in the Practice of Law. Introduction to Centrifugal Force. Invention and Operation of a Stone-dressing Machine.

ENGINEERING REMINISCENCES

Birth, Parentage and Education. Experience in the Practice of Law. Introduction to Centrifugal Force. Invention and Operation of a Stone-dressing Machine.

Iwas born in Auburn in the State of New York, January 18th, 1826. My parents were both of New England descent. My father, John Porter, was born in Hadley, Mass. His father, William Porter, was the son of Eleazer Porter and his wife Susannah, one of the daughters of Jonathan Edwards. My father’s mother was Lois Eastman. My mother was born in Middletown, Conn. Her maiden name was Abigail Phillips. Her ancestry in the maternal line is traced back to Governors Saltonstall, Dudley and the two Winthrops.

I graduated at Hamilton College, New York, in 1845, read law in my father’s office, and in the fall of 1847 was admitted to the bar. Practiced my profession for six or seven years, first in Rochester, N.Y., afterwards in New York City.

My knowledge of mechanics may be illustrated by a story I once heard in England of a man who had been prosecuted for selling adulterated tobacco. He got off by proving that there was no tobacco at all in the article that he sold. But this illustration hardly does the case justice.

I had some mechanical ideas, but they were exactly wrong. For example, I could not see any difficulty in perpetual motion. All one had to do was to pump up water, which by its fall would furnish power to run the pump. This, however, was no more absurdthan were two inventions which were brought out in England while I was there. One of these was corrugating the faces of the piston, so as to present more extended surfaces for the steam pressure to be exerted upon. The other was a device for utilizing that half of the force of the steam which had been wasted against the cylinder heads. Both of these were published with commendatory remarks in theMechanics’ Magazine. The last, if I recollect rightly, was the original bottom feature of the Wells balance-engine. My error was that I made no account of friction, which must be overcome before motion can take place. We shall see before long the same disregard of friction by men who ought to have known better.

My utter ignorance of everything mechanical at that time is capable of proof. I stepped right into one of those “springes to catch woodcocks” which were being set in those days, and proved myself to be about as green a gosling mechanically as ever was plucked.

I had a client by the name of Searle, who was a “dead-beat.” He owed me about $100, which I could not collect. He finally called upon me and told me frankly that he could not pay me one red cent, because he had no money; but he could put me in the way of making a fortune, and he was anxious in that way to discharge the great obligation which he felt himself under to me.

A new invention had appeared, called the Gwynne & Sawyer static-pressure engine, that was bound to revolutionize all applications of power. It was, he told me, attracting great attention in engineering circles, and there had been a hot discussion over its theoretical principles, but its advocates had successfully vanquished all their antagonists and now the invention was established on a perfectly sound scientific basis. If I would give him a receipt in full for the money that he owed me and put another $100 into this enterprise, he was in a position to secure for me a number of rights to use the machine. He kindly offered to introduce me to Mr. Sawyer. Mr. Gwynne was unfortunately absent from home at the time. (I learned afterwards that he was in jail.) Mr. Sawyer received me most graciously. I think he had been told by Mr. Searle about how much taffy I might be expected to swallow, but he must have ventured far beyond his instructions.He told me that he was delighted to make my acquaintance; he had frequently heard of me through our mutual friend, Mr. Searle, and of my triumphs at the bar, and had come to feel a great admiration for me, and was proud to show this great invention to a man so eminently capable of appreciating it. He told me that the invention was a practical method of utilizing that wonderful power known as centrifugal force. This force could be obtained in any amount. In fact, it was the force that kept the universe in motion. It had lain unutilized for so long a time because engineers had never been able to apply it practically. This difficulty had been completely overcome in this great invention, and this wonderful power was now to be made available for the world. He gave me quite an oration on the subject, saying, “We do not antagonize the forces of nature, we utilize them and apply them to beneficial purposes; consequently all nature co-operates with us,” and more to the same effect. He was able to show me a working model of this great invention; was very sorry that he could not put it in motion for me that day, as it happened to be a little out of order; but I would be able to see the principle of its operation very distinctly. I was flattered into believing that I saw the principle, with the result that Mr. Sawyer saw the principal, and with the further result that after that I never saw or heard of either principal or interest. Our mutual friend, Mr. Searle, also disappeared.

This was my first lesson in mechanics, given to me by a master of his art. I am not sure, on the whole, but that in one way and another it has been worth the trifle it cost me.

Had any one at that time told me that the expression “centrifugal force” is entirely misleading, that in reality there is no such force, that what goes by this name is not a force at all, nothing but a resistance, the resistance which a body revolving around an exterior point opposes to being continually deflected from a straight line of motion, and which ceases the instant the deflecting force ceases, when the body merely moves on in a straight line tangent to the circle, and in bodies revolving around their own axes or centers of gravity is the same resistance of their atoms, he would probably have had about the same success in making me see it that I long afterwards had with some engineering friends.

It is difficult at the present day to conceive the confusion of thought which then prevailed on this subject. The language of text-books was vague in the extreme.

The coincidence is not without interest, that my first mechanical experience, though in this ridiculous fashion, should have been with what was to become so prominent a feature of the high speed governors and engine.

I had for some time felt a growing disgust with the profession of the law. The contrast between the glorious science of human rights and the art of its practical application was very forcibly presented to my mind. I realized the fitness of the protest of Bryant, who described himself as being “forced to drudge for the dregs of men.” I was a regular reader of theEvening Post, in which an article appeared one day, written by John Bigelow, then the editor of thePost, laudatory of a certain judge whose term on the bench had lately closed, and who then retired from the profession. On this act Mr. Bigelow warmly congratulated him. Among a number of pungent expressions in the article I was particularly struck by this one: “The association of lawyers is mostly with knaves and fools.” My own experience bore witness to the truth of this statement. A few legal successes, which cost me incredible labor, interspersed of course with disappointments, weighed nothing compared with the daily association which I seemed compelled to endure. I formed a scheme for establishing a conciliation office for the amicable settlement of disputes, but found every man prepared to compromise on the extreme verge of his own position. So I gave that up.

I had another client, a Mr. Hastings, who had invented a stone-dressing machine, which he had patented, and the patent for which he wanted to dispose of. He had a working model of his invention, which was operated for visitors in the shop where it was built. He invited me to go and see it, which I did, and it certainly worked very well indeed. I recalled afterwards that the stone was carefully bedded on the table of the machine. I was quite fascinated with it and took some friends to see it, who were equally captivated, and the result was that we bought the patent. To make sure of its value, however, I first called with Mr. Hastings on Mr. Munn,his patent solicitor, and received Mr. Munn’s assurance that he had a very high opinion of it.

I gradually abandoned my law business, and devoted myself to the exploitation of this invention. I put into it all the money I had and all that I could borrow. After a while a large working machine was completed for us, the drawings for which I had made by a German draftsman, and which was built under my direction at the works of Mott & Ayers, near the foot of West Twenty-sixth Street. When this machine was finished the parties in interest assembled at these works to see it tried.

One experiment was enough. I had put into the machine a stone that was quite a foot thick and which was supported at two points. At the first cut made across this stone it broke in two in the middle. I found myself, in the words of President Cleveland, “confronted not by a theory but by a condition.” The machine was absurd. The patent was worthless. The enterprise was a failure. Our money had all been thrown into the sea. Nothing could be done unless I did it; and I knew nothing of mechanics, of machine design or construction, or of mechanical drawing, except the little that I had picked up in the works of Mott & Ayers while this machine was in process of construction. I should say, however, that the head draftsman in that establishment had given me some instruction in mechanical drawing, so that I knew the use of the instruments and what kind of ink to use.

I cannot recollect that I was in the least cast down or discouraged. I cannot now account for my confidence. I believed that the fundamental features of this machine were correct. These were: cutting stone by a blow given by a hammer moving in an inclined direction, and which was thrown up by a cam and thrown down by springs. The more I reflected upon it the more I became convinced that a successful stone-dressing machine could be made on those general lines, and in no other way; and I also became impressed with what seems the almost absurd conviction that I could make it.

The machine that broke the stone had a broad hammer—a cast-iron plate with tongues on the sides running in grooves in a frame,and to the end of which a long steel blade was bolted. My first idea was to divide the single broad hammer into several hammers working side by side and striking their blows successively; the second was to separate the hammers from the tool-holders, the third, to employ the same tools that were used by stone-cutters, namely, the point, tooth-chisel and drove, and to give them as nearly as possible the same blow that was given to them by the workman, and the fourth, to give to the tools only the blow necessary to do their work.

I infused my own enthusiasm into my associates to such a degree that they agreed to put up the money and let me try the experiment. That also is something that I now wonder at.

The most influential member of this devoted band was George T. Hope, President of the Continental Fire Insurance Co., a gentleman whom I shall have frequent occasion to mention, and who remained my steadfast friend till his death, which occurred soon after the close of my engineering career.

I set about my work in this manner. My house, on the south side of Twenty-second Street west of Seventh Avenue, had been arranged in its construction to use the extension room back of the parlor as a dining-room. That left the front basement available for me. This I equipped for a drawing-office, and set myself at work to learn mechanical drawing, and at the same time to design this machine. I bought a Scotch instruction book, and a sheet of “antiquarian” drawing-paper. In those days all drawings were made on white linen paper, and this was nearly the largest size that was made, and cost 75 cents a sheet. My principal drawing-implement was india-rubber. As my plans grew in my mind I had to rub out my preceding sketches. I spent a great deal of my time in visiting the large engineering works on the East River—the Allaire Works, the Morgan Works and the Novelty Works—and studying tools and machines and principles and methods of construction. I tried to get my mind saturated with mechanics. I finally succeeded in producing the design, this vertical section of which I have sketched from memory after fifty years.

It will be seen that this machine was massive in its construction. This was required on account of the speed—300 rotations of the shaft per minute—at which I had determined to run it. This was my first employment of high speed.

George T. Hope

The original model of the machine made 60 strokes per minute. In the machine that broke the stone I had increased the speed to 100 strokes per minute. In designing the successful machine I made the great jump to 300 revolutions of the cam-shaft per minute. This was done after much study of practical requirements. I observed carefully the speed of planing-machines. I had also the opportunity of witnessing the operation of the first wood-moulding machine, and was much impressed by the speed of the rotary cutters and the rapidity with which the work was turned out. I wanted a motion of 40 inches a minute for the stone table, which would make the output of the machine satisfactory; 300 revolutions would give this motion, the table advancing .133 of an inch at each blow.

Side frame not shown, except Channelsfor Elevating ScrewsMy First Mechanical Drawing.Longitudinal Section of my Stone-dressing Machine.

Side frame not shown, except Channelsfor Elevating Screws

My First Mechanical Drawing.Longitudinal Section of my Stone-dressing Machine.

The machine contained six hammers, each 6 inches wide and weighing about 200 pounds, which ran in a suspended frame. The front member of this frame was a wrought-iron bar 6 inches square, with a projection on the lower side, asshown. At the ends this bar was first reduced to 5 inches square, the corners rounded to 1 inch radius, and mortised into cast-iron side-bars 4 inches thick, one of which is shown in the sectional view. Beyond these side-bars the wrought-iron bar was turned down to journals 3¹⁄₂ inches in diameter, which turned in the heads of large screws, one of which is represented. Beyond those journals it was further reduced to 2 inches diameter, and the ends threaded. These projections extended through slots in the main framing, and nuts on the outside provided with long handles enabled the whole to be bound fast in its position, when that had been determined.

The hammers had two faces; the upper faces struck on this 6-inch square bar, the lower faces struck the backs of the heavy tool-holders. These tool-holders were held in position in the mannershown. At the extreme back end they rocked downward upon a heavy cross-bar. At the front they rose against the 6-inch cross-bar. They were made with a heavy hook at the back, which prevented them from coming forward further than the projection at the bottom of this cross-bar permitted. A curved spring held them up to the cross-bar when the weight of the hammer was removed. Between the 6-inch cross-bar and the tool-holders and the hammer faces I introduced a sheet of heavy leather belting, which deadened the force of the blow. A stone-cutter uses a wooden mallet to drive the tooth-chisels and droves, because the impact of iron on iron has a disintegrating effect upon the stone, which the stone-cutters call “stunning the stone.” It produces a vibration in the body of the stone to a depth of perhaps ¹⁄₈ inch, and, however well the surface of the stone may appear when it is finished, after a while the outside will flake off to the depth to which these vibrations have extended. This leather buffer served the purpose of the wooden mallet, completely avoiding this difficulty. Incidentally also it made the building habitable, by transforming the blow into a dull thud, which at the rate of 1800 blows per minute from the six hammers was itself quite important to be done.

The large screws on each side of the machine at the front were provided at the top with long nuts resting on a cross-bar and combined with worm-wheels. A shaft carrying two worms engaging with these wheels extended across the top of the machine, so that the nuts were rotated identically, and the front of the suspended frame was raised or lowered as the thickness of the stone or depth of the cut required. The machine could cut stone from the thinnest ashlar up to a thickness of about 3 feet. The hammers ran on rollers asshown. At the back the frame and hammers were carried on similar rollers on the same shaft. The ends of this shaft also turned in square heads of screws, and by a mechanism similar to that already described the back of the frame could be elevated or depressed to the height required and be set at any desired angle.

The six tool-holders were made in the following manner: I got from England a bar of steel long enough to make them all. This was planed into the form shown in thesection, and the sockets for the shanks of the tools were finished to an equal depth and perfectly in line. It was then parted, and the ends of each finished in a slotting-machine.

The blows struck by the hammers were very effective. The cams had a throw of 1¹⁄₄ inches, but they threw the hammers back against the springs 1¹⁄₄ inches further, making their fall 2¹⁄₂ inches. This I ascertained by holding a piece of thin board edgeways between the upper end of a hammer and the cross-bar at the back, when the hammer crushed it up to this height.

We never ran over the stone with the points but once. They made everything before them fly. On the other hand, the droves merely dusted the surface, to take out the marks of the tooth-chisels. All surplus force in the blow was received on the 6-inch cross-bar. The tools stood motionless unless pushed back by the stone, when they received a sufficient portion of the blow to drive them forward to their position.

The feed motion was powerful, being imparted by a worm engaging in a worm-wheel 24 inches in diameter, while the run back was swift, quite 100 feet in a minute.

The sides of the steel tool-holders, rubbing against each other, became after a while badly abraded. I was obliged to planethem off and dovetail thin strips of hardened steel into them. These prevented any further trouble. The sides of the end tool-holders, however, which rubbed against the cast-iron side-bars, I observed, were polished without sensible wear.

This was a very important observation. These surfaces all rubbed together dry. The pressure was only the side thrust, which was very trifling. Under these conditions the molecules of the same material interlocked, while those of the different materials did not. These two materials were, however, extremely different in their constituent features. Perhaps this point of freedom ofsomedifferent materials from interlocking was still better illustrated by the set-screws, where this difference of molecular structure did not exist in the same degree. These were made of Ulster iron, a superior quality of American iron then largely used in New York City for bolts. They were ⁵⁄₈-inch screws, and were also used dry, no oil being allowed anywhere over the stones. Each tool-holder contained three of these set-screws. The outside ones were tightened and loosened sixty times every day. The middle ones, where only the points were used, were tightened and loosened twenty times every day and at other times stood loose in their threads. The tool-holders being massive, and the blows of the hammers also coming on the leather cushion, there was no vibration. At the end of the two years’ running the outer bolts were all perfect fits. The middle ones were loose, but still held the tools perfectly.

The rollers on which the hammers ran were hardened and turned on hardened shafts. The hammers themselves had chilled faces, and their surfaces running on the rollers were also chilled. The surfaces of the tool-holders and of the bar on which these rocked were provided with hardened strips to the extent that they came in contact with each other. The cams and rollers and their pins were also hardened.

When built this machine was found to require only a single alteration. I had welded the cams onto the shaft, the welds being guaranteed by the smith to be perfectly sound. No appearance of unsoundness could be detected when the shaft was finished, but after running a week or two the cams became loose. This also gave me a useful lesson. I was obliged to send to England forblocks of steel, which were bored, finished and keyed on the shaft in the mannershown, and the working surfaces of the cams were hardened. This required the substitution of new hammers, because the cams could not be threaded through the old ones. The hubs of these cams were 6 inches long, covering the shaft.

Our company, being satisfied from its design that the machine when finished would prove a success, rented from Mr. Astor a large lot on the south side of Fourteenth Street, west of Ninth Avenue, extending through to Thirteenth Street, and erected and equipped a building and established a stone-yard, where the machine ran successfully for two seasons, principally employed in facing ashlar, as the flat-faced stones of buildings are termed. It turned out with ease 600 square feet of finished surface per day, which was the work of thirty men, and it never broke a stone, however thin.

For facing in the machine the stones were set on bars 2 inches thick and 4 inches high, cast on the surface of sliding tables. These were both longitudinal and cross bars, and were provided with holes ³⁄₄ inch in diameter and about 3 inches apart. There were two tables, each 16 feet in length.

Several pieces of ashlar were set upon each table and held by dogs and wedges on these bars. They were wedged up very easily by skilled workmen, so that they would finish at the same level. At one side of the ways on which the tables moved, near each end, was placed a swing-crane, which was double- and triple-geared, so that by means of it any stone that the machine was adapted to cut could be lifted by two men. The operations of cutting the stones on one table and removing the stones and setting others on the other table went on simultaneously, so that the cutting was never interrupted, except to change the tools and the tables. This last was done as follows: Each table, when the work on it was completed, was run rapidly backward or forward to attach it to the other table. It was then connected with this by a couple of hooks, and, the motion being reversed, pulled it into place under the tools, and in doing this took its own place under a crane, so that the work of removing the finished stones and setting rough ones went on continuously at one end or the other of the ways.

In addition to the machine I designed the building and thewhole plant and the plan of its operation, which moved like clockwork. I made every drawing myself. The cranes I obtained in Rochester, N. Y., of a pattern which the builders made for railroads for handling heavy freight.

I bought from a stone-dressing company that had failed a rubbing machine called the Jenny Lind rubber, from the fact that it was started the same year in which that songstress was brought to the United States by Mr. Barnum. This rubbing-machine was quite a success. From a central vertical spindle a jointed arm extended in three lengths, each about 12 feet long. The sections of this arm were very deep, so that there was no sag at the end, where the rubbing-plate was driven by belting and could be moved from stone to stone around a circle of 36 feet radius. Half of this circle was sufficient for our use. I made only one change in this machine. The pulleys, two pairs on each joint, one at the top and one at the bottom, about two feet in diameter by three inches face, were of course horizontal. The makers were afraid the belts would fall off; so they made these pulleys with two square grooves, ¹⁄₂ inch wide by ¹⁄₄ inch deep, in their faces, and had corresponding strips of leather sewn on the belts to run in these grooves. I threw all these away and substituted ordinary pulleys with their faces slightly crowning. Never had the least trouble. Indeed, these pulleys did better than I expected. I supposed the belts would need to be taken up occasionally, on account of becoming stretched, but they did not. Perhaps they would have done so if the strain on them had been greater. This rubbing machine resembled the stone-dressing machine in one respect: everything about it was arranged for continuous operation and the largest output.

The business was carried on the first season under the management of Mr. John McClave, a master stone-cutter, and the second season under the management of the firm of Brown & Young, stone-cutters. Mr. Hugh Young, of this firm, has since been prominent in the stone-cutting business in New York.

The machine was found to possess a remarkable advantage over hand work. The sun was called by stone-cutters “the great revealer.” When its rays fell at a small angle on a surface finishedby hand they showed very considerable irregularities. The same test showed work in the machine to be true planes. It won a high reputation; stone-cutters were anxious to get their surfaces done in the machine, and we had more work offered us than we could do.

The following incident illustrates the favorable impression made by the machine upon everyone who witnessed its operation:

At a meeting of the Directors of the Company at which I was present Mr. Daniel S. Miller, a gentleman somewhat prominent in financial New York, was late. He made the following explanation. “I thought that before the meeting I would visit the stone yard and see how the work was going on. I stayed longer than I had intended, and I want five thousand dollars more of the stock of this company.”

We were much elated over our success, and plans were made for enlarging the business. I completed the drawings for an additional machine, wide enough to take in platforms, for which provision had been made by me in the plan of the building. The only change suggested by our two years’ experience was the use of air-cushions behind the hammers in place of steel springs.

But the best-laid schemes o’ mice an’ men, the poet tells us,

“Gang aft a-gley;And leave us naught but grief and painFor promised joy.”

“Gang aft a-gley;

And leave us naught but grief and pain

For promised joy.”

Our plans were suddenly ruined. A change in the method of facing ashlar was introduced and soon became universally adopted. Instead of being faced by hand, it began to be sawn out of large blocks. I have since wondered why this had not been done long before. Blocks of marble had been sawn into slabs by gang-saws no one knows how long, and all that had to be done was to apply the same system to blocks of building-stone. It was found to cost no more to saw ashlar than it had done to split it out at the quarry. All the cost of facing and much stone were saved. Our stone-cutting machine became useless, and I learned that disappointments were not confined to the legal profession.

The speed of 300 revolutions per minute had proved to be admirably suited for the machine. Familiarity with this speed in the running of the stone-dressing machine made me alive to the value of high rotative speeds in all cases to which they are adapted.

In looking back over this period I see that the success of the stone-dressing machine was due to the following causes:

First, I went about the work of facing stone by machinery in the natural way.

Second, the machine was superabundantly strong and substantial in every part.

Third, it was made with absolute mechanical truth.

Fourth, the speed was splendid.

Fifth, the blow was peculiar. In the Hastings machine the cutting-tool was driven into the stone. In mine it rested on the stone and was moved back horizontally by the feed. This changed slightly the angular position of the tool-holder, so that the blow was received by it at the lower edge of its back. This gave to the tool a motion forward andupward, so that the vertical effect on the stone was trifling.

This was the vital feature of my improvement, and that in a double sense; for it was only by convincing my associates beforehand that a machine operating in this manner could not break the stone that I was able to obtain their financial support.

Sixth, the two-faced hammer saved the stone from all unnecessary force of the blow.

The final cause of its success was the two-table system. The two operations of setting and cutting occupied each about the same time, and twenty tables each averaging thirty square feet of surface, measured after being squared up, were easily finished in a day of ten hours.

A description of some of the constructive methods employed by me may be interesting:

The bar of steel which was to be made into six separate tool-holders had to have eighteen sockets mortised in it. These were 1 inch square. I had made the tools with square shanks so as to insure their proper position. These mortises must be absolutely in line and of equal depth. These objects were accomplished as follows: A cast-iron angle-bar with planed surfaces was first boltedon the table of the drilling-machine, and for drilling the holes the bar of steel was kept in contact with this angle-bar. A uniform depth was insured by employing a bottoming-drill with a collar formed on the shank. The drilling was finished when this collar rubbed on the steel bar.

I had this work done by Mr. Joseph Banks, whose shop was in a large building at the corner of Second Avenue and Twenty-second Street. Mr. A. S. Cameron, the inventor and manufacturer of the celebrated Cameron steam-pumps, was then an apprentice in that shop. Mr. Banks was an excellent mechanic, and I was greatly indebted to him for the accuracy of the work that I procured. He devised an expanding-drill to cut a groove at the bottom of these sockets, in which the chips from the slotting-tool made in squaring the holes would come off. The finishing slotting-tool I designed myself. I had noticed in all slotting-machines that came under my observation at that time that the tool would spring off a little at the commencement of the cut, so that a full square angle was never obtained. To avoid this defect and to size the slots equally I made a slotting-tool to cut on opposite sides. The cutting edges were each about ¹⁄₈ inch long and the corners rounded. The bar for the tool-holders had to be set three times on account of its length. It was set in contact with the same angle-bar, which was bolted on this table parallel with its transverse feed. This finishing-tool being once set, the upper and lower faces of all the sockets were thus readily finished in perfect line and with square edges. The tool being then turned at right angles to its first position, for which purpose its shank had been planed square, finished the sides of the sockets. These were identical in every respect, and any tool could go anywhere.

The springs behind the hammers were prepared with great care. I had large bars of spring steel reduced under a tilt-hammer to a section ³⁄₈ inch square. These were coiled with only ¹⁄₄ inch space between the coils, so that in case a spring broke within the hammer it could not get out of place. These springs were exceptionally durable. We took off the back cross-bar occasionally—perhaps once a month—to examine for broken springs, and sometimes we found one, which was replaced with a new one because we assumed that it was fatigued, but the hammersworked just as well with broken springs as they did with whole ones. The springs, having considerable initial compression, did not become loose.

It seems proper to add that, except the help from Mr. Banks, I did not in designing the machine or organizing the work receive assistance or suggestion from anyone.

With these details I bid a final good-by to you, my old schoolmaster. I have a warm place in my heart for you. You set me my first lessons in mechanics. Your life was short. You were not ordained to cut much of a figure in the world. But you were faithful. You always did your work and did it well.

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