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cut run about 2" each end beyond the point where the stem would travel when in use. The job was to get a gland and junk-ring on that stem so that they would fit. This is how it was done: A brass bushing was sawed through longitudinally, and the joint filed to a fit. I then with soft solder sweat them together, using the slightest quantity of solder. I then bored this bushing to fit the stem, and turned it to easily fit the original junk-ring, which had been previously bored out and recessed, as shown in Fig. 164.

When finished, the bushing was warmed to melt the solder when it fell apart. I then slipped the ring H over the valve-stem I, and placed the two parts of the bushing G in place. It will of course

Fig. 164

H

G

G

H

Fig. 163.

be understood that when in the stuffing-box the packing will prevent this bushing from moving, so that for all practical purposes it is as good as if it were all solid. The ring J which fits in the bottom of the stuffing-box is made in the same manner as that of G, except when put on the stem a drop of solder is used to join it; but when once inside the stuffing-box it does not matter whether it is in two pieces or one. Some builders of steam-engines excuse themselves from not making that part of the valve-stem that works through the stuffing-box" at least larger than the rest, on the ground that the area presented for the steam to act upon will be too great and will be attended by an excessive wear of the valve motion. All I have to say in this connection is that, within the practical limits here intended, the above argument has no value, for unless a piston valve or other means of balancing are used, it would take a pretty large-sized valve stem to offer a sufficient surface for the steam to act upon in overcoming the friction. of a slide valve upon its seat. Sufficient stock should be allowed, and so distributed that valve-stems may be trued up several times before they are thrown away.

The practice of making the threads on the ends of piston-rods of equal diameter with the rest of the rod ought to be condemned for several reasons. The principal one is that the rod cannot be trued up and used without resorting to a spilt gland bushing; and when metallic packing is used it is necessary to remove that packing whenever the piston-rod is taken out of the cylinder. The reason is that the threads on the end of the piston-rod would tear it all to pieces in drawing it back through the stuffing-box. If the thread were of a smaller diameter than the body of the rod, as it should always be, then there would be no necessity of disturbing the packing, and the rod could be trued and replaced, requiring only a plain bushing for gland and for junk-ring.

The above engine, when first set up, rested on a bed of sulphur, against my remonstrance; but we were told that there were hundreds of steam-engines set in the same way. The thickness of sulphur between the feet on the cylinder and the stone capping on the foundation was ". After two years of service the sulphur began to disintegrate and work out. The engine had to run every night, so whatever we concluded to do in the line of repairs had to be done between the hours of 7 A. M. and 4 P. M. For information I asked about a dozen engineers of my acquaintance as to what they would do under the circumstances. The answers I received have induced me to put this in print, for I would have been very grateful had any one told me off-hand of the method that I employed to secure this engine permanently on the foundation. One friend says, "Make a rust joint," forgetting that it takes three or four days for a rust joint to harden sufficiently to be sure that it would not disintegrate and come out. Another says, "Put in cement," knowing full well that cement requires a week or ten days to become hard. Still another says, "Wedge up the cylinder and run in cement, and let the engine rest on the wedges until the cement hardens." He knew that wedges are the worst things that could possibly be used to support a

piece of machinery that is constantly vibrating, for they do work loose. Finally one friend says, "Put in more sulphur," arguing that it would last as long as the original, which was certainly good logic; but this did not suit me, for I wanted to make a permanent job of it.

I went home and meditated, and the next morning I went to the machine-shop and had four pieces of flat iron 4" x 1" cut off. These I reduced in thickness so as to just fill the space between the top of the cap-stones and the cylinder feet. I dug out the sulphur by the side of each anchor bolt, of which there were four, two in each foot; I slacked the nuts of the foundation bolts, then put in my liners, one for each bolt, and screwed them fast.

The sulphur was then removed from one foot at a time, and the space thoroughly scraped out. We then took two strips of lath and wrapped sufficient paper around each of them to fill the space between the stone and foot, thus dividing the space into three equal parts. This was done because it would take more metal to fill the space than could have been conveniently handled. We placed strips of lath edgewise all around the foot, and backed them with fire-clay. An opening was left at each of the four corners-two for risers and two diagonal corners for pouring metal, leaving a head of about two inches to better ensure a solid casting. Some powdered resin was thrown into the gates to absorb the moisture and prevent the casting from blowing. Having previously melted in an iron pot a mixture composed of nine parts of lead, two of antimony, and one of bismuth (commonly known as expansion metal), we poured from two ladles and in about ten minutes had the satisfaction of finding that our cylinder was as securely held as if it had been originally bedded on the solid stone. We poured the outer spaces of each foot first, then removed the two strips of lath and poured the middle space, the two outside castings forming the dam preventing the metal from running out at the sides. No one who has seen it doubts that this cylinder is fixed forever. Some persons will say that they have been setting engines on sulphur for the past decade and none of them came loose. Grant it; but ours came loose! and let me urge this assertion-that an engineer does not want to have an engine-bed work loose on the foundation but once in a lifetime. Let an engine-bed be fitted as closely to the stone as possible; then, after leveling, put a thin grout of good cement into the cracks, if any are left, to equalize the strains upon the bed-plate when the nuts are tightened on the foundation bolts. Where the

bottom of casting is rough, or the top of foundation has not been fitted to the engine-bed, the engine should be leveled and supported upon liners (not wedges) and the nuts screwed up lightly. Then pack in well-mixed cement and slabs of roofing slate until all the cracks are filled. It takes about one week for this mixture to get hard; but it is cheap and durable, and while it is hardening the other work of cleaning and putting the engine together can go on without interruption. During the past twenty years I have set up a great deal of heavy machinery by bedding in this way, and after the cement had hardened I took careful measurements and found that the beds had not moved or sprung. I have yet to hear of my first piece of machinery set in the manner just described coming loose or giving any trouble whatsoever.

While I think of it, I wish to mention a curious circumstance that occurred in connection with our heater connections. The engine cylinder for some unknown reason began to cut, and the small steam ports in the cylinder of our steam pump became stopped up. Subsequent examination revealed the fact that a steam valve in the pipe connecting with the scum chamber of the heater for the purpose of blowing it out, was badly out of order, so that the scum and grit arose and backed up into the steampipe, and were carried thence to the pump and engine. I at once had the pipe separated, and it is connected only when we wish to blow out the heater. After this is done the pipe union is slacked up, so that if there were any leak it would appear at once. This involves the use of two globe valves instead of one. My experience in this direction led me to conclude that it is an exceedingly dangerous thing to connect the steam pipe leading to pumps and engines with heaters, because, if there should happen to be a leak at any time, the grit and dirt are almost certain to cut all the cylinders.

These few practical suggestions seem to prove that while we as engineers are unquestionably advancing in some directions, we are retrograding in others.

DISCUSSION.

Mr. Oberlin Smith.-Upon this paper I merely wish to take up one of the good points discussed, and say that we can, none of us, attach too much importance to the practice of designing all the reciprocating members of machines so that the termini of rubbing services will "wipe" past each other, as Mr. Lyne terms it, thus

preventing the abominable evil of "shouldering." This I learned very early in my engineering experience, by being obliged to crawl inside of the box frame of a 120 H. P. horizontal engine to chip and file away the lower side of the flat guides, for about 1 inch at each end, because these guides were about 2 inches longer than the stroke plus the length of the cross-head brasses. The upper side was easy enough and was a good place to learn delicate chipping. The operation had to be repeated at intervals of a month or two; and as the conglomerate of black grease, furnace ashes, and brass dust usually lay about an inch deep in the confined space within the frame, and was of the consistency of rich molasses, the job was not a pleasant one. Of course, the trouble could all have been remedied by three inches of common-sense applied in shortening the guides, or lengthening the cross-head by that amount, thus giving half an inch to wipe over at each end.

In the building of punching presses and other machinery having reciprocating slides, I always pay particular attention to this point. The only case where it cannot be properly carried out is where a slide has an end adjustment greater than its stroke, although in practice the different positions to which it is adjusted at different times will usually average up the wear, so that there is no trouble.

I think the best plan in all such constructions is to come as near as possible to following out the principle, advocated more than once by Professor Sweet before this Society, of making both members of a sliding mechanism the same length. For instance, a nut should be as long as the threaded part of its screw, etc. This principle is difficult to follow in some cases, such as a lathe carriage upon its bed, where the traverse is very long compared with the limit of length necessary in the carriage, but it is well to keep the idea in mind wherever possible. In general, too little attention is paid to shouldering screws down to a diameter as small as the bottom of the thread in all parts not subjected to actual wear. Not only do members of a machine, which reciprocate upon or within one another without the ends "wiping" past, wear to a "shoulder," but they also wear out of parallel, as shown in Mr. Lyne's rod, Fig. 163.

Mr. W. J. Creelman.-The portion of Mr. Lyne's paper relative to bedding engines on sulphur is interesting to me, from the fact that his experience with that material is in direct opposition to my own. Our practice, generally, is to use sulphur for bedding engines, but in a thin body allowing not more than one-sixteenth

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